| Author |
Message |
    
Hotwire
Advanced Member
Username: Hotwire
Post Number: 959
Registered: 1-2005
| | Posted on Thursday, February 23, 2006 - 7:37 am: | 
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Found a good deal on one. Having swr trouble though. Anyone ever trim the stinger? Did it help? Should I trim the Stinger or keep working for a low swr? |
Kmt36264
Junior Member
Username: Kmt36264
Post Number: 20
Registered: 1-2006
| | Posted on Thursday, February 23, 2006 - 7:00 pm: |
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Most cases, almost a foot has to be removed. It is much simpler if you can get an analyzer. |
Hotwire
Advanced Member
Username: Hotwire
Post Number: 961
Registered: 1-2005
| | Posted on Friday, February 24, 2006 - 12:56 am: |
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Wow! Before I go and chop a foot off I will sell it and get something else! |
1861
Intermediate Member
Username: 1861
Post Number: 457
Registered: 2-2004
| | Posted on Friday, February 24, 2006 - 10:48 am: |
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DEPENDING ON WHAT LENGTH SHAFT AND SINGLE OR DUAL COIL , IT VERY WELL COULD NEED THAT MUCH TRIM . IT COMES WITH LONG STINGER TO BE ADAPTED TO ALL DIFFERENT LENGTH SHAFTS AND COIL CONFIGURATIONS . |
Hotwire
Advanced Member
Username: Hotwire
Post Number: 962
Registered: 1-2005
| | Posted on Friday, February 24, 2006 - 10:56 am: |
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Well I think I got most the bugs worked out. Last night the local SSBers had trouble understanding me. SWR was OK with amp on but with it off it was totally unacceptable. So I tossed out my 2 foot jumper and bought a premade 3 foot jumper.Prices at truck stops are rediculous but thats another story! Also changed radios. My old 148 has been through 4 winter and 3 summers. ONe car accident, 3 mics and many many hours of use. Maybe its just to old and tired? The new 148 using Astatic 600 meter has an SWR of 1.5 to 1.8 with amp off or on. I'm happy with it now although the 148 with its little 1969 final goes real easy driving the 4 2879's. I see an S 9 in my future! Thank goodness I had not trimmed my beloved Predator 10K! Radio checks are good AM and still have yet to see SSB performance. NOW! Where is all the DX? |
1861
Intermediate Member
Username: 1861
Post Number: 459
Registered: 2-2004
| | Posted on Friday, February 24, 2006 - 1:16 pm: |
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HOTWIRE , WHICH COIL AND LENGTH SHAFT DID YOU GET ? |
Kmt36264
Junior Member
Username: Kmt36264
Post Number: 21
Registered: 1-2006
| | Posted on Friday, February 24, 2006 - 7:29 pm: |
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The reason you are seeing OK swr with amp on is that the radio is only looking at the input SWR of the amp. The AMP is still seeing bad SWR and you will eventually see smoke. Don't sell the antenna...just tune it. All the cowtown stingers are too long by design. Take the amp and jumper out of line (if you are using the radios built in SWR meter) and tune the antenna. If you can get an analyzer, you can verify the resonant frequency and start cutting in 1" increments. When you get close to resonance on your frequency of choice, stop cutting and zero it in.
There is nothing wrong with the antenna. If an 102ss is out of the question, the predator is the next best thing. |
Hotwire
Advanced Member
Username: Hotwire
Post Number: 967
Registered: 1-2005
| | Posted on Sunday, February 26, 2006 - 11:54 am: |
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1861,
Sorry man I been busy. I have the 27 inch shaft single coil.
Kmt36264,
You are right. SWR was high after the amp. Been conversing with Patzerozero about his Predator install and things are coming along well. I did set everything up with radio to antenna only and SWR is 1.2 to 1.5 1-40 channels. Put the amp inline and SWR stays the same regardless of the setting. Works satifactory but with all the NON DX downtime I have I'm going to work at getting the best performance by effiency possible. So far I have not trimmed the whip. Its all the way down so I think I may trim maybe half inch sections at a time. Not decided yet. Gonna get some better coax 9913 and look for a stud mount to get rid of the So239 first.
I wish I would have bought a Predator sooner! A 102 inch is the mack daddy I agree but I'm actually seeing better in recieve and transmit with the Predator versus the 102 inch whip I have. The biggest improvment is being able to hear the local stations that just was not there before. Maybe I'm crazy or maybe I'm just doing something right but I'm a believer in the Predator. |
Dale
Intermediate Member
Username: Dale
Post Number: 331
Registered: 12-2002
| | Posted on Sunday, February 26, 2006 - 2:12 pm: |
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seems thepreadator is a liked antenna wonder
why coppers dont carry them |
Bigwheel
New member
Username: Bigwheel
Post Number: 8
Registered: 10-2005
| | Posted on Monday, February 27, 2006 - 12:25 am: |
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I love my 10k have it mounted my toolbox i noticed a big improvement on recieve and transmit also can't wait till it warms up outside so i can took up my 600hd |
Kmt36264
Junior Member
Username: Kmt36264
Post Number: 22
Registered: 1-2006
| | Posted on Monday, February 27, 2006 - 9:03 am: |
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I do seem to make more contacts with new, distant stations with the Predator than with the 102'. The problem I have is with reflected watts. My CB antenna is a few feet away from my 2m ant and where the 102 seems unaffected, the Predator doesnt like the other antenna. |
Vanillagorilla
Intermediate Member
Username: Vanillagorilla
Post Number: 486
Registered: 4-2005
| | Posted on Saturday, March 04, 2006 - 9:25 am: |
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For me anyway...having variable power at my fingertips worked things out quick. I still trimmed my stinger around 6-7" to bring it into spec but having the variable to TUNE the input made it go a lot quicker...as long as you keep the input at a safe level 
If your talking to Pat about this then I should just forward you all my emails from my install 
I feel like I just got my Jeep setup right and NOW I went and popped it on the roof of a Dodge Ram...back to the drawing board! Yesterday I saw a totally UNACCEPTABLE SWR and wondered what went wrong...I swapped the antenna for a little glass stick I had and they improved. Pulled the 10k and brought it down to the basement to check things out. Seems water from the snow storm we had yesterday had slipped down the stinger and into the shaft. After it all defrosted I poured it out like a canteen! Have since loaded the shaft hole with dielectric grease and made a little rain boot for the stinger...all is well again.
Get that 10k set up right mr Wire and you'll love it. I didn't even realize how much better my RX got until I was told I'm "hearing things" that are not there. Now that the 10k is hooked to a MAGNUM radio in the mobile with the 10k 2ft higher and the fact that I just last night built a external speaker with HEADPHONE jacks on it (stop laughing Pat! ) I should be able to hear you all again on Sundays...in the mobile anyway  |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2507
Registered: 7-2004
| | Posted on Saturday, March 04, 2006 - 11:08 am: |
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!
have not had the least bit of trouble with my SWR's when the base has been covered with snow & ice. remember, i removed the SO239 & went lug mount. though it's coated in liquid electrical tape, i'm sure it gets wet when encrusted in ice. still, no troubles. the ONLY trouble i've had with SWR's were when ice completely enclosed both coils! 2:1 SWR's, up from <1.1:1 was quickly reduced back to normal by a few keys of heavy duty RF  yup, you could SEE the ice melt |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 553
Registered: 11-2002
| | Posted on Sunday, April 23, 2006 - 5:13 pm: |
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***Tech 833 notes***
The following post is VERY subjective and with no scientific fact to back it up. Please read accordingly.
----------------------------
I gotta put my two cents in here. In no way can a 102" whip compare to a Predator. The Predator (in my opinion) beats anything out there, hands down.
My only problem with one I have is it's height. Low over-passes knock it over or off even with a tri-mag mount. Been thinking of drilling a hole and making it permanent, but what'll happen when I go under those same over-passes? It would suck to rip a hole in the roof of my truck.
Heck yes!!! Receive and transmit are way better with a Predator. Walks the dog on my Wilsons, and I've had the 1000 and 5000, truckers & mag mount. Even a Lil Will, though I have no idea why they make that thing.
You won't find a better antenna, period. Just like in my opinion you won't find a better radio than an S9. Hmmm...wonder what Pat put in those brownies he sent me? |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1359
Registered: 7-2004
| | Posted on Sunday, April 23, 2006 - 6:12 pm: |
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Last Wednesday we did tests on around 10
different mobile antennas. Yes, the 10k was
very close to performance with the 102" whip.
But, by no means did the 10k surpass the
performance of the 102" whip.
I'm not a big 102" whip fan and in most installs
they are not even practical and i would never
run one. But, there hard to beat! |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2756
Registered: 7-2004
| | Posted on Sunday, April 23, 2006 - 7:11 pm: |
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i posted real world testing done with a bunch of mobile antennas on a local beach. no fancy equipment, just, get the SWR's low as possible & see how i sound & how the other station sounds to me. i won't get into THOSE results again. but the 102" didn't fare well at all, in fact, high SWR's rendered it useless.
i know there are 'professional' comparisons of TYPES of base antennas, & even some of PARTICULAR antennas, probably more for 10m then 11m, but i'm sure results would be similar, if not exact(5/8 better then 1/2 better then 1/4 better then a tree branch, etc). BUT, are there any 'professional' comparisons of mobile antennas??
while 833 is correct that there is no scientific fact to back up 'chops claims, mine, or anybody elses, i think 'real world' comparisons may be better for mobile antennas. how often is your car in 'free space' with the antenna perfectly situated for a perfect radiation pattern? i see on a daily basis my predator, roof mounted, producing a stronger signal then a higher powered car with a 102" whip rear bumper mounted on a corner.
is it possible for my 84" + predator with the large, open, exposed coil to make up for it's slightly shorter length due to physical size as compared to the skinny piece of wire of a whip? i said my astatic 3k was close in performance to the predator, though it proved worthless with much power behind it, & the 7' fiberglas skipshooter also was right there. but that was parked on the beach. might as well throw a base antenna up, but you can't when you're moving. the performance difference of the predator or any 7'+ antenna is VERY easy to see vs the wilsons & k40 etc. people i could not hear 70 miles away on a wilson 2000 can be talked to just fine with the predator, in the same location. i am almost embarressed to say, but, yea, there was in some cases a 2+ S-unit gain with the predator. same wattage out also improved copiability of my signal the same 2 or more S-units in some cases.
while scientific fact says a 1/4 wave antenna stretched out straight is better then one shrunk down with a coil in it, i'm not so sure that real world use will agree. i'd like to see an antenna tester do it with mobile antennas, in a parking lot, on a beach, but i just can't picture him hanging onto the roof at 70mph.
they say people who spend too much money on something have no choice but to brag about it, but a wilson 5000 could conceivably cost more then the predator, & i've spent money on antennas that cost well over $100 as well as some that cost closer to $10. while i wouldn't mind something a little less attention-getting on my roof, nearly 30 years of trying mobile antennas has me still sold on my predator. |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1360
Registered: 7-2004
| | Posted on Sunday, April 23, 2006 - 8:54 pm: |
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Pat, i'll be setting up a new mobile system.
I'm leaning toward the 10k or Mr.Coily.
I had no trouble with Swrs on the roof mounted
102" whip or its performance. But,i don't
care for them and probably never will.
Pat, what size shaft do you have on your 10K and
where's it mounted on your vehicle??? Thanks |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1361
Registered: 7-2004
| | Posted on Sunday, April 23, 2006 - 8:59 pm: |
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Pat, i re-read your post and see you have
your 10k on your roof. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2760
Registered: 7-2004
| | Posted on Sunday, April 23, 2006 - 10:39 pm: |
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22" double coil. doesn't seem to show ANY difference vs my 17" single, just a couple inches shorter. the mr coily would probably pull the magnets right off the roof. the predator is more of a stealth big coil antenna and i really saw no difference between coily, predator & monkey-only size & weight. |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1363
Registered: 7-2004
| | Posted on Monday, April 24, 2006 - 12:39 am: |
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That's the results i got from testing.
Didn't care much for the Monkeymade (weight).
Yeah, i seen no difference between Coily and
10k. The coily dx are alittle, but, not much heavier than the 10k and performed the same.
I was only using the 102" as a guide. I spent
extra time getting it set-up to work correctly.
But, everything fell in ok after awhile.
Thanks for the info PAT! |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1227
Registered: 1-2005
| | Posted on Monday, April 24, 2006 - 12:59 pm: |
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102 inch whip is supposed to be THE antenna and in my opinion the next best thing is the Predator. Its advantage over the 102 is that you can tune it by adjusting the stinger. I have always had trouble with swr and 102's. Predator was a breeze to tune. I am a believer in the Pred now! Its my antenna of choice. No others will satify me now I have used one. One worry I have is theft. Its very hard to find one around here to buy off the shelf. You must order one and I'm the only one that I know of in my area who has one on there car! Truck drivers have even commented that they want my antenna driving down the road even offering to buy. If I go to a truckstop I bird dog my car all the time now. If I have to go to a parking lot or garage for very long I just remove it. I would not be suprised if one day I got off work or woke up to find it missing!
Porkchop, I would drill a hole to mount your Predator. I drilled a hole in my trunk and supported it with sheet metal underneath. I have hit a few things and because the stinger is so long it just whiped underneath and came back uo with no damage. Unless you was going REALLY fast I would not worry. At least since I have mine on the trunk I can open the trunk to lower the antenna if needed.Worked out well. Anyways good luck! 73 |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1364
Registered: 7-2004
| | Posted on Monday, April 24, 2006 - 6:54 pm: |
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I've never gotten a 102" below 1:3:1 (SWR).
My new antenna will be roof mounted with
a 6"x6" coily mount. |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 554
Registered: 11-2002
| | Posted on Monday, April 24, 2006 - 9:38 pm: |
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What makes my post VERY subjective?
I stated my opinion, nothing more or less. I've tried a few antennas myself and I can't help that Pat convinced me to try a Predator and it's the best antenna I've ever owned.
I can put my Wilson 5000 Trucker on the exact setup I have, same mag mount and antenna mount tuned to the same SWR as my Predator. During almost exact weather conditions during exactly the same time of day, a guy nearly 20 or so miles away said he heard the difference. I was louder and stronger on the Predator versus the Wilson.
I can hear way better on the Predator than I can think of hearing or hope to hear on my Wilson. Not to mention that the Predator does look a lot better than anything Wilson has to offer.
And when you try the 102 and the Predator and hear the difference yourself, what more proof do you need? I said "my opinion" and I didn't say it was the "gospel according to Porkchop".
Somewhere I read that a 1.3:1 SWR on a 102 is as low as it will go. And you can get lower on the Predator although I haven't got mine below a 1.2:1 I believe is correct. |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1365
Registered: 7-2004
| | Posted on Monday, April 24, 2006 - 11:02 pm: |
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I understand why you like your 10k so much Porkchop.
They are a very nice antenna. No doubt!
1:2:1 is good.
Where do you have yours mounted on your vehicle? |
Tech833
Moderator
Username: Tech833
Post Number: 1334
Registered: 8-2002
| | Posted on Tuesday, April 25, 2006 - 12:29 am: |
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TRPC- Because you said "You won't find a better antenna, period.", that is why I said your post was VERY subjective.
I'll bet that if you looked around the Copper warehouse, you could find an antenna or two that would outperform the Predator. To say an antenna is the best, period is highly subjective. |
Im4jc
Intermediate Member
Username: Im4jc
Post Number: 143
Registered: 11-2005
| | Posted on Tuesday, April 25, 2006 - 10:20 am: |
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How does the Predator perform going down the road at 75 MPH for hours on end? Does it become a static generator with that open coil design? Or are you guys doing most of your tx/rx sitting still or driving around at city speeds? |
Thehobo
Member
Username: Thehobo
Post Number: 76
Registered: 2-2004
| | Posted on Tuesday, April 25, 2006 - 12:47 pm: |
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833, id almost agree with your post of p/c post, but he did say in his opinion!! to me i wood take that as he, trpc, really likes his 10k, no way wood i accept that as gossple?? so to me its how a person wood look at and read into what he said?? i to like 10ks!! i have put it up aginst about 15 different mobil antennas of all types and in the comparision with a base 25 miles away very few came close to the 10k, now this is in my opinion, my way of testing, witch ill agree is very unsintific!! its just 2 old boys playing with what they got and seeing the results as is?? something i believe trpc did!! anyway not to ruffel anymore feathers ill leave it for each to dicifer?? my nickles worth..
thehobo
274150 am
monitor ch. |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1236
Registered: 1-2005
| | Posted on Tuesday, April 25, 2006 - 1:12 pm: |
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Road Warrior, Your Coily mount? Are they very hard to install? Do you have to wire the coax to it or does it have the so 239 threads to accept a pl259? |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1368
Registered: 7-2004
| | Posted on Tuesday, April 25, 2006 - 2:44 pm: |
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Well, you should have a vehicle that you plan on keeping, not one you plan on selling or trading.
It requires a 1" hole, then 4 other 1/4" holes.
Have to wire the coax. Simple though.
Not many people are willing to drill 5 holes...LOL... My car is what i call a throw-away.
Will keep it until death-do-us part. |
Road_warrior
Senior Member
Username: Road_warrior
Post Number: 1369
Registered: 7-2004
| | Posted on Tuesday, April 25, 2006 - 2:51 pm: |
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Hotwire- A triple magnet mount works too.
IM4jc-I did drive the car at 65 mph during testing, didn't notice anything unusual, expect
for my car needs a front end alignment... |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 556
Registered: 11-2002
| | Posted on Tuesday, April 25, 2006 - 5:28 pm: |
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The vehicle it's mounted on is 2004 Sterling dumptruck.
First off at 85 mph I don't have any trouble with it, blowing off or producing static. I don't and won't drive my truck loaded or empty that fast for a real long time period, so I can't say exactly that it does/doesn't produce static.
I have mine set up on a tri-mag mount. I use Predators lug mount setup. The only problem I've had with that is due to the height of the antenna, I've broke the center conductor off the eyelet once. I have since added a cable clamp about 3 inches from where it connects to the mount and haven't had that problem again.
I'm running LMR400 Ultra Flex coax and cut it to length by Pat's math. The jumper from the S9 to the Dave is also by Pat's math and it's the stock coax from my Wilson 5000 mag mount. I had a lot of feedback into my FM stereo before, and changing the coax helped A LOT!!! After that I added some grounding and that iced the cake so to speak.
About finding a better antenna at Copper, I won't say I won't. But I'll ask this 833, how about you recommend one then? Maybe something as good OR better that isn't quiet as tall. I've removed my 10K cause it's so tall. And now back on the Wilson 5000 Trucker, I can hear that I'm not picking up things as clear as before. I hear more static and more noise than readable signal.
In no way did I mean that all or any of the antennas sold by Copper were 'bad' or 'junk' because Copper doesn't sell a Predator. I'm pretty sure there isn't but so many ways to "correctly" build an antenna, so there are probably others out there as good and maybe better. But I haven't found them yet.
Plus consider this. The whole entire Predator doesn't weigh what a Wilson 5000 Trucker weighs. It's like picking up a handful of feathers as where the Wilson is like picking up a 5lb bag of sugar. And even if you poured the whole bag on the Wilson, to me it still wouldn't be as sweet as the Predator. Again, just my opinion.
With the triple mag though, I still problems with the Predator getting knocked over and beat around. The Wilson isn't as bad cause it isn't as tall. But it does happen now and then.
As far as my opinion goes, I'd only recommend Times Microwave LMR cable right now (for the money) over any other coax in that price range. And I would say that it's way better than any of that truck stop coax or Rat Shack coax you can buy. There is a difference for sure. |
Wildrat
Advanced Member
Username: Wildrat
Post Number: 860
Registered: 12-2003
| | Posted on Tuesday, April 25, 2006 - 8:05 pm: |
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Pat, why did you go to lug mount? I have both a monkey Made and a Predator. After I get the SS rear tire carrier mount made next week I was thinking of trying the Predator. What do you think of the two antennas Pat? Monkey Made vs. Predator? I've had both Fiberglas and SS 102" whips. The Fiberglas one whip was better with my application. I think with these antennas in the real world the differences are with your setup. What I am saying is, is that something may work really well for you and perform terribly for someone else. I would go as far as to say even identical setups will perform differently, same vehicle, radio, coax etc. Man built the stuff, man may have been hungover when tightening bolts in the factory that day. China man may have a cold solder joint on the radios board, The antenna may have been made from a different pile of aluminum, SS, or Fiberglas. Hotwire if you need another jumper let me know I'll build ya one, you just come and pick it up. Actually I'm going to start offering my help to fellas on the local channel, when I'm outside soldering I'll let them know and they can stop but and I'll solder for them. It seems quite a few have difficulties with soldering anything. |
Tech833
Moderator
Username: Tech833
Post Number: 1337
Registered: 8-2002
| | Posted on Tuesday, April 25, 2006 - 10:15 pm: |
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Hi TRPC.
Recommendation? This is going to tick-off some people, hopefully not Copper....
For a good performing short antenna, I prefer the Signal Engineering Lightning mobile. If looks are a concern, then the Shakespeare top-loaded fiberglass whips. They are not continuously loaded like the Firestiks, they are only top loaded. |
Marconi
Advanced Member
Username: Marconi
Post Number: 649
Registered: 11-2001
| | Posted on Wednesday, April 26, 2006 - 11:20 am: |
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833, I think that is the Golden Rod 45 or 50 that you are talking about. The Lightning is their beam line of antennas. I have never owned one, because I don't do mobile anymore. I have thought about getting one just to check them out however. They are a very interesting design and I like the new 50 model look. |
Tech833
Moderator
Username: Tech833
Post Number: 1338
Registered: 8-2002
| | Posted on Wednesday, April 26, 2006 - 12:35 pm: |
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You are correct- What is now called the Golden Rod 45.
Long time ago, it was the lightning mobile. I am terribly behind the times. Thanks! |
Tech237
Moderator
Username: Tech237
Post Number: 301
Registered: 4-2004
| | Posted on Wednesday, April 26, 2006 - 3:26 pm: |
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Hotwire,
before cutting the stinger sacrifice a coat hanger and once you have the right length cut the stinger to much.
Much cheaper and coat hangers we dont really worry about - do we? |
Tech237
Moderator
Username: Tech237
Post Number: 302
Registered: 4-2004
| | Posted on Wednesday, April 26, 2006 - 3:31 pm: |
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Pat,
Did you do teh comparison with the 10K on the roof and the 102" bumper mounted or did both antennas use the same mount?
If using different mounts in different locations then yes a roof mounted antenna should perform better than one bumper mounted - becuase it is in the clear and not next to a large piece of metal.
try the tests again and use the same mount for both antennas and see if you ge the same results. |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1245
Registered: 1-2005
| | Posted on Thursday, April 27, 2006 - 12:54 pm: |
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Simon, Hmmm not a bad ideal. Luckily I did'nt need to cut! I would need one BIG coat hanger! I will keep that one in my archives for future reference. thanks |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 565
Registered: 11-2002
| | Posted on Saturday, April 29, 2006 - 2:02 am: |
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Well, I won't say that those antennas aren't as good or better than my personal choice.
I was die-hard Predator before a phone call yesterday. After that phone call, you couldn't give me any other antenna.
That's just my personal thoughts and opinion though. I'm not trying to talk anyone into a Predator nor am I trying to put down any other brand/type of antenna. I really liked Wilson antennas before...but now I say "Wil-what?".
If a Predator is giving me height problems, can you imagine what a problem I'd have with a 102 on my dumptruck? Boy howdy!! |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2787
Registered: 7-2004
| | Posted on Saturday, April 29, 2006 - 11:32 am: |
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WOW!!!
go back to my 4/23/06 7:11PM post above...i do NOT have ALL the answers, and i feel my question/thought on real world vs antenna-testing-ground for a mobile antenna needs to be done by somebody who can do it.
try to answer as best as i can here-
with my current predator mounted as shown in members pics(the ONLY way THIS antenna has been mounted), i've cruised at 75+ mph for as long as 6 hours with maybe 1 fuel stop, & my single coil 17" while on my blazer went to fla at least a dozen times, as well as myrtle beach maybe 6 times, about 1500 & 800 miles each way. no static buildup whatsoever. vanillagorilla hears me regularly while moving in the 70mph range, as well as parked. on DX, as confirmed by CEF members, i've been parked, rolling, & cruising at highway speeds, & the only adverse effects i may encounter are the traffic i lights i have to stop for whenever i talk to kid vicious in vegas, & my voltage starts to plummet .
i said i was embarressed to say it, but i HAVE seen a 2 S-unit increase both RCV & XMIT. not sure how accurate a measurement of signal stength increase that really is though. have seen that kind of increase with 1-5 S-unit signals. higher strength shows less increase, but it also pulls 'no copy' to 'very copiable' S1-S3 strength.
when i go somewhere like shea stadium, i stop a few minutes from the ballpark, unscrew the antenna, remove the radio & discreetly cover them up. if i'm going to a really bad spot, i can also remove the mag mount.
i don't think i really NOTICED any difference between any of the big coil antennas i've used. predator, monkey, coily, northstar 20k, galaxy 25k, solarcon 25k, wagonman, crowbuilt, & who knows how many others. some were harder to get below 1.3:1, while coily, monkey, predator ALL go right down to 1.1:1 or less, & reflect of less then 2% with dead keys from 1w to a whole bunch 'o watts.
i said i liked my 7' skipshooter-fiberglas with a tuning tip. while it was difficult to achieve 1.3:1, it was EXTREMELY close in performance to the predator, rcv & xmit-wise. as for 102" whip? i never saw under 2:1 (maybe even higher).
ALL of my testing done last year was on the roof with this same setup. previous testing was done on 1 of my blazers, mounted as wildrats jeep pics show, with coil just above 'glas roofline. results were the SAME. NEVER used a bumper mount, above wheel well on 1 blazer, 'glas roof didn't cause any radiation problems, but highly directional. trunk mounting was only done on wifes car. rentals got the scratched roof treatment.
i had flip-flopped back & forth between pl259 terminated coax, & lug mount numerous times. i found PL259/SO239 easier to change out, BUT seemed to change ends frequently, even with NOALOX & other suggested coatings. seems as though that stuff, watter, oxidation, crud etc do not mix well with high amounts of rf, & cause poor connections, arcing, high swr, & other assorted maladies. spoke to kale when i went 22" double & he RECOMMENDED lug mount with noalox or other coating as it seems to oxidize much less, crud stays out, & you appear to have a better ground. have not had to change lug on this setup in 18 months, & my last setup blazer had lug mount for close to 5 years.
as for not being able to get same performance on different vehicles, i disagree. my xl, previous davemade & 17" single predator was on 3 different blazers, with the same swr's, reflect, wattage & performance. my 22" dual with same xl & different davemade performs with same swr/reflect, max out, & expected performance. i have helped setup over 2 dozen predators in the last 2 years, some on mag mounts, some hardmounted, at least 6 via email or phone, the rest actually being there. some owners had difficulty & required assistance, some had no problems, ALL tuned to 1.3:1 or less over 40, most that i actually helped with got right down to 1.1:1. while i did get CEF669's wilson's swr's down to 1.2:1 or less fairly quickly, that is not always the case with them. the predators just hit that #! i took a wagon with a predator & dx1600 that was showing 1600 watts on dosy, showed person a few hundred less on SX100, but also 75%+ reflect. OUCH! a couple hours of rewiring, replacing coax & adjusting, dropped reflect to 3%, & wattage showed an honest 1kw. his DX ability went from none to all, & local contacts were no longer limited to a few miles(with what he thought was 1.6kw!). while performance from 1 vehicle to another may not correspond to equipment used, it very well can be made to do so. time & patience. & you can't rely on man to be perfect every time. you have to do it yourself sometimes .
as for the SE mobiles...do you really think that tiny little, horizontally polarized, coil loaded loop is going to show 1.5-3 db gain over a dipole? at much less then 4' above the roof, a bit less if you mounted off the bumper or over a 'glas roof, swr's of under 2:1 were almost impossible to obtain. way up high & they did come down to 1.3:1 or so. nor could i expect that thing to handle 10kw or whatever they claimed. the performance of the 7" skipshooter & dr crowbuilt was by far better then that of the original golden rod on DX. it also was not good for local talking, to vertical antennas. will have to dig out the triangle shaped new golden rod to take a pic. was too embarressed to even try that one myself. don't have the shaft anymore though. came in handy for stickball i think. they should have built a full sized horizontally polarized loop, at roughly 5' on all sides, it would fit on a full sized van or truck. i suppose SE's got the right idea with the golden rod's, just poor execution.
chop's phone call refers to customer service. predator is 2nd to none. i think kale even gives sam lewis a run for his money in that dept. DEFINITELY 2 people to deal with.
finally, take a 7' tall antenna, at about 5' from the ground to its feedpoint, even with a few extra watts, & get the signal reports that mine gets regularly, local & dx, &, if you can fit it, you'll be convinced. oh, gets in there on less then 4 watts real good too. |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 582
Registered: 11-2002
| | Posted on Thursday, May 04, 2006 - 6:55 pm: |
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Got my new 2 coil yesterday.
Oh yeah...another winner!!!!!!
Juggs gotcha!!!!! |
Jameslarson
Intermediate Member
Username: Jameslarson
Post Number: 104
Registered: 4-2006
| | Posted on Thursday, May 04, 2006 - 8:29 pm: |
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Sounds great. How did you mount it? What length coax from antenna to amp? radio to amp? Thanks. |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 585
Registered: 11-2002
| | Posted on Friday, May 05, 2006 - 12:24 am: |
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I'm the Juggernaut...my suit is tight
Oh.
I mounted it on the same mount I had the single coil on. The coax from the radio to the amp is 12Ft. And from the amp to the antenna is about 14.6Ft. I went with the lug mount when I originally ordered my single coil.
I needed a little shorter antenna cause I have to load my truck under silos. And some over-passes around here are kinda low. The double coil is more than short enough and so far I can't tell the difference between the two.
How you like my ship....it's a Dodge |
Jameslarson
Intermediate Member
Username: Jameslarson
Post Number: 107
Registered: 4-2006
| | Posted on Friday, May 05, 2006 - 10:13 am: |
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Hi. Did you pick that coax length for SWR reasons, or simply that is just the length you needed based on where the equipment is mounted? Thanks. |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 590
Registered: 11-2002
| | Posted on Friday, May 05, 2006 - 11:08 am: |
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Well I figured the length off a formula I got from Pat. I've since seen the same thing listed somewhere on the net. From what I saw, it was for making dipoles in like 1/2 waves or something.
I also read on the same page that you could use it to figure coax length to keep the coax from being an impedance repeater. Where, if I'm wrong somebody chime in, the mismatch at the antenna (too long or short or whatever) would be increased on the meter. Meaning that if the coax was an impedance repeater, it would multiply the mismatch and show a higher SWR on the meter than you actually had.
In turn driving you crazy trying to tune your antenna. I guess maybe it would be possible that it showed a lower SWR and you actually had a higher one. I don't know though.
I do know that using the LMR400 coax just about knocked all the feedback into my stereo out. I have been picking up noise from my AC blower motor and switching to the Predator knocked that down some too. I still hear it if I turn it up on the 3 or 4 selection. But before on low or 1, 1 real bad, I could hear it and it was over-riding incoming signals bad.
Plus I know that you could buy an antenna made by someone else or from somewhere else and if you had problems you would more than likely be on your own. I know from experience you can email Kale or even call him and he'll try to help you out personally himself. How many other antenna builders will do that? How many others will build you an antenna based on your problem and vehicle? How many others will send it to you without you paying for it and trust you to send them the original one back?
To me, even if there is one out there that is just a little bit better (and I doubt it) after dealing with Kale and talking to him personally. I won't ever buy any other brand antenna. You don't find people like him anymore and when you do you need to thank them and respect them. They are a dieing breed... |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1306
Registered: 1-2005
| | Posted on Friday, May 05, 2006 - 12:24 pm: |
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Hey James! Interested in the Predator 10K huh? Once you go Predator you'll never look at your old antennas the same way again!
Not trying to hi-jack Porkchop now but with mine I used enough rg213 to neatly route it around the passenger compartment and circled the trunk once with extra in case I ever need it. My main coax is 20 feet long and the jumpers are 3 and 6 feet for a total of 29 feet! SWR and coax length is all hype! The stinger is the only way to tune the Predator! So far its performance is awesome and puts my Wilson silverload to shame! Just yesterday I made a DX contact to Argentina with around 200 to 300 watts! Bet I could have gone barefoot! |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2813
Registered: 7-2004
| | Posted on Friday, May 05, 2006 - 4:40 pm: |
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length(in feet)= 468 divided by freq in mHz times velocity factor of coax...or for channel 6, 468 divided by 27.025 equals 17.32 feet times 84% velocity factor of 9913 equals 14.55 feet...then always use an odd multiple of that length, 14.55 feet, 43.65 feet, 72.75 feet, etc
no debates please, they asked for the formula so there it is
'I'm the Juggernaut...my suit is tight'-are you on druuuugs, mr gambini(herman munster in my cousin vinnie....) go easy 'chop |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 597
Registered: 11-2002
| | Posted on Friday, May 05, 2006 - 8:07 pm: |
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I didn't say that you used coax length to tune an antenna. I agree 150% that coax length does nothing to antenna SWR or even actual SWR. However it's out there that coax length can cause an impedance repeater and give a false SWR reading. I know you can't believe everything you see on the net. But I did see a dancing baby, a squirrel singing about gonads and strife and Yoda smoking tweeds. That would explain why he talked in riddles and backwards all the time!
I gotta say I agree with Hotwire about the performance. If it doesn't slap everything overhead, you'll love it. Everybody should go out and buy one. If you don't like them, Pat and myself will buy them back from you, ha-ha. |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1211
Registered: 6-2004
| | Posted on Saturday, May 06, 2006 - 10:34 am: |
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468 is an approximation for making 1/2 wave dipoles out of various metals, and it's just a starting point. Trimming is usually necessary. It sort of takes the velocity factor into consideration so the calculation is simpler.
The correct formula for a 1/2 wavelength is 492 divided by the frequency in MHz to get the length in feet, and then multiply by the velocity factor of the coax or wire to get the correct 1/2 wavelength.
So for coaxial cable with a velocity factor of .84 on a center frequency of 27.025 the math is:
492 / 27.025MHz = 18.205365402405180388529139685476 feet * .84 (velocity factor) = 15.2925069380203515263644773358 feet or 15.29 feet rounded to two decimal places. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2817
Registered: 7-2004
| | Posted on Saturday, May 06, 2006 - 7:52 pm: |
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page 100 of 'practical antenna handbook' by joseph carr, 1989(i hope antenna theory hasn't changed in this respect over 17 years...)-in free space half wavelength is found from....using 492...in a perfect antenna ....492 will yield the physical length. but in real antennas the length calculated is too long...a more nearly correct approximation is...using 468. this is for finding 1/2 wavelength to build a dipole antenna. lou franklin says that due to capacitive differences at the ends of the transmission line(or antenna), 492 & 468 are both dependent on each particular case. but, 468 is the closest approximation for finding 1/2 wavelength of dipole antenna or 50W transmission line. |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1213
Registered: 6-2004
| | Posted on Saturday, May 06, 2006 - 10:53 pm: |
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Velocity factor is a fractional value relating a transmission line's propagation speed to the speed of light in a vacuum. That's why you use 492 - it's the number you would use to calculate the length in a vacuum.
468 is an approximation that takes velocity factor into consideration so the calculation is easier. |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 610
Registered: 11-2002
| | Posted on Saturday, May 06, 2006 - 11:54 pm: |
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My suit is tight |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 611
Registered: 11-2002
| | Posted on Sunday, May 07, 2006 - 12:03 am: |
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google "the juggernaut" and you'll see what I'm talking about. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2822
Registered: 7-2004
| | Posted on Sunday, May 07, 2006 - 9:03 pm: |
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not sure which scares me more, the SC death metal, or the comic book character....or could it be....therealporkchop
practical antenna handbook, arrl amateur radio handbook, the mobile hf companion, & lou franklin all say 468 to use for calculations & then multiply by velocity factor for coax length. or i could use the premade 18' piece of 50% shield rg58 that comes with the radio shack magnet mount & use my davemade to light up my dashboard like a pinball machine while front & rear windshield wipers flap like a duck that got hit by half a load of #9 shot from a .410 at 150 yards |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1216
Registered: 6-2004
| | Posted on Monday, May 08, 2006 - 11:00 am: |
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I checked "Understanding and Repairing CB Radios" and you are correct Pat, Lou Franklin uses 468 to do coax length calculations. He's wrong. Velocity Factor or "Velocity of Propogation" is referenced to the speed of light in a vacuum, so you would have to use 492 in the calculation.
But don't take my word for it, look it up on the internet to see for yourself. Check Belden's, Times Microwave's, or any other cable manufacturer's website. I have. They all define Velocity of propogation as a measurement of a signal through a physical medium referenced to the speed of light in a vacuum. |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 621
Registered: 11-2002
| | Posted on Monday, May 08, 2006 - 11:20 am: |
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Word up Pat! I've had the "Pinball Machine Onboard" sign hung in the window a many a day.
You guys remember the 3 Stooges episode where they were getting married and that guy told them "hold hands you love birds"?
Pat & 455...Hold hands you love birds!!
Can't we just all get along? Don't look at me like that young man....oh you're gonna get it. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2824
Registered: 7-2004
| | Posted on Monday, May 08, 2006 - 5:15 pm: |
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i can't solder inside a vacuum. nor do i think i can 'get out' any better if i use 492. the arrl handbook says 468, & we all KNOW not to question the arrl
easy 'chop...it'll be OK. we're at least 150 miles apart besides, 10% of the time me & hollow agree |
Dale
Intermediate Member
Username: Dale
Post Number: 371
Registered: 12-2002
| | Posted on Tuesday, May 09, 2006 - 10:00 am: |
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DID YA USE AN ANTENNA ANILYZER 2 TUNE THE ANTENNA
opps sorry about the caps,with the anylizer i highly dought you see any difference when change
coax lenth and an anylizer checks everything from coax loss too ohms 2 impedence
dale/cef426 |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1217
Registered: 6-2004
| | Posted on Tuesday, May 09, 2006 - 10:21 am: |
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My point is that the definition of velocity factor or velocity of propogation as it's apparently called in the industry, is referenced to the wavelength of RF in a vacuum. Therefore it's necessary to use 492 to be accurate because that's how the manufacturers calculate the velocity factor.
Whether you care to do it that way or not is beside the point, and I don't doubt that folks use 468 all the time and get serviceable results, but that also is beside the point.
Nearly every reference that I've seen use 468 as a starting point is for making 1/2 wavelength antennas, and it's usually mentioned that it's an approximation and trimming will be necessary.
No ill will here. We're merely arguing a rather fine point about a subject we sort of agree on. |
Therealporkchop
Advanced Member
Username: Therealporkchop
Post Number: 631
Registered: 11-2002
| | Posted on Tuesday, May 09, 2006 - 5:09 pm: |
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How you like my ship....it's a dodge!
My suit is tight...
google - juggernaut dubbing |
