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Message |
    
Wolverine
Intermediate Member
Username: Wolverine
Post Number: 190
Registered: 2-2003
| | Posted on Thursday, June 17, 2004 - 2:37 am: | 
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I was just curious, and you can check my profile to see what amps I already own. Question: What is a good all around happy medium (power figure In watts) for reliable ground wave communication, and skip shooting?. Some would say 1000 watts, others would say 100 watts. I want to pass this info on to my friends buying their first amp. Thanks in advance.
Wolverine. |
Tech808
Moderator
Username: Tech808
Post Number: 2676
Registered: 8-2002
| | Posted on Thursday, June 17, 2004 - 10:45 am: |
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Wolverine,
It all depends on conditions and your setup.
Last Sunday Bandit CEF #268 was able to reach Pig040 in Roswell, NM. from Central Ill here with my 4 watt 100% Stock Washington Base and Stock Un-modulated mic, with a Mobile Anttron A-1700 antenna mounted on his roof.
With the New MAGNUM S-9 I am Testing we have hit PA, FL, WA, VA, MS, OH, NC, NY, SC, OK, Canada and other spots with 35 to 45 watts from the Stock Radio & No AMP.
Your Antenna and setup and a good Pre-amp is a Major factor along with the radio you choose for shooting skip.
When conditions were good I ran the CEF Nets with my Stock Teaberry Stalker Two dead keying 4 and swinging 8 watts and the 1st Sargants Ranger 696F SSB Base dead keying 2 1/2 swinging about 6 watts.
I ran these for several weeks and had great contacts and reports running barefoot even connecting with Kiwikid in New Zealand for several weeks in a row.
I give most of the credit for these contacts to my SE beams and Anttron 305.
A KL 300, 400 or 550 will all work great added to about any system and the Pre-Amp is a MUST for DXing.
Just my thoughts,
Lon
Tech808 |
Airplane1
Junior Member
Username: Airplane1
Post Number: 33
Registered: 5-2004
| | Posted on Thursday, June 17, 2004 - 3:19 pm: |
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Hi,
what would be a good preamp for use with a klv 400
base amp?
Thanks, airplane1 |
Bruce
Senior Member
Username: Bruce
Post Number: 1280
Registered: 9-2003
| | Posted on Thursday, June 17, 2004 - 11:56 pm: |
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Well a number of people have heard me on cb with my stock grant lt ( 4 watts) and all i run on 80- 10 meters is 100 watts TO A DIPOLE ...... 100 on 6 meters and 65 watts on 2 meters....... TO A VERTICAL |
Wolverine
Intermediate Member
Username: Wolverine
Post Number: 192
Registered: 2-2003
| | Posted on Friday, June 18, 2004 - 3:04 am: |
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You're right Lon. Conditions and set-up are key. I've shot skip with 4 watts from San Francisco (Stock Radio), and to my surprise I got a comeback from Texas. I use my amps only in heavy traffic, and on channels where the competition is stiff. I'm going to print this, and pass it on to my friends who feel that they need a grand (1000 Watts), just to enter into this hobby. Thanks.
Wolverine. |
Tech808
Moderator
Username: Tech808
Post Number: 2679
Registered: 8-2002
| | Posted on Friday, June 18, 2004 - 9:01 am: |
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Airplane1,
Most moblie and base amplifiers already come with a built in Pre-Amp in them.
The KL-400 is a Mobile Amp and also has a built in pre-amp.
Lon
Tech808 |
Bullet
Intermediate Member
Username: Bullet
Post Number: 343
Registered: 7-2003
| | Posted on Thursday, June 24, 2004 - 4:15 am: |
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i think most people look at how to "get out" with thier radios all wrong or at least backwords.
the first thing we turn to is that instant gratification switch (FIL. ON )and then we flip that standby and rock and roll. lol
if you want to do some serious ground wave, you need a serious antenna system or an array of antennas.
this is alot more work than installing a box inline.
"why most people dont do it" and opt for the imax and a kilowatt.
but you can only talk as far as you can hear. and a school bus in the sky will capture alot more signal and any ole copy stick could ever hope to.
he with the most TRUE db's wins!
take gain figures from the leading manufacturers in the cb market with a grain of salt.
thier far from being anything close to the real gain of those antennas. its dream gain. but the fact is bigger is better. and a 5 elements beam at 10db will flat do you a better job than a imax |
Bullet
Intermediate Member
Username: Bullet
Post Number: 344
Registered: 7-2003
| | Posted on Thursday, June 24, 2004 - 4:55 am: |
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put up the biggest meanest beam or beams you cant afford and put them up as high as your nerves will allow you to go on some good tower thats guyed very well(youll need it) buy the very best coax cable you cant afford throw in a preamp and a box of some sort and your in thier.
heres a few examples of stations around local, some guys i talk with use.
one fella uses a set of 2 signal enginering lightning 4's on a 70 foot tower and 9913 coax i believe and has a kilowatt amp.
another uses a home brewed 6 elem quad at 110 feet
browning radio(great ears)ceramic 4cx250r box with pre amp as a driver...for a big box 9913 coax.
my plans still are to finish building my tower and put up my home brewed 4 elem quads at about 100' and my 2 meter stacked array in between them.
ive got lmr600 for the quads need some more for the 2 meter array
my 60 foot tower has my colinear arrays on it.using 9913 and mini8 for the 2 meter super j poles very lossy but its all i had around at the time. plan to up grade to lmr 400 for the 2 meters.
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Dindin
Intermediate Member
Username: Dindin
Post Number: 215
Registered: 2-2004
| | Posted on Thursday, June 24, 2004 - 8:51 pm: |
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Bullet,
I know what you mean by the examples.one local here runs an Excalibur into a highly modified Maco400(now holds a shoebox full of 8950's)I've witnessed doing 1.5kw on am,into rg-8x to an antron99 40 feet agl.he talks ok into Fla and up the coast and thats about it.have offered to help him set it up right but he is happy like it is.have often tried to convince him a dollar on the tower is worth more than 10 on the desk. |
Bullet
Intermediate Member
Username: Bullet
Post Number: 346
Registered: 7-2003
| | Posted on Monday, June 28, 2004 - 2:52 pm: |
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dindin,
1.5kw into rg8x. whew look out hope he's not a long winded fellow. i bet he splatters his neighbors quite well and is well liked.
i see it the same way as you and thats a good way to put it."one dollar on the tower is worth 10 on the desk".
you can have 2kw on the desk and run a antron at 40 ft and get out good but how far can he hear!
not very far compared to a beam at 70-100ft. hight is might and bigger is better.lol
have a good one dindin
bullet |
Geekster
Member
Username: Geekster
Post Number: 81
Registered: 6-2004
| | Posted on Wednesday, July 21, 2004 - 7:56 pm: |
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Ground wave distance is very difficult to predict. Sky wave you can predict somewhat for non-skip conditions. Skip conditions are very unpredictable.
Confused yet? I know I surely am!
try this link
www.kb8ygc.com/Power.pdf
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Bob_p
Junior Member
Username: Bob_p
Post Number: 22
Registered: 7-2004
| | Posted on Wednesday, July 21, 2004 - 10:12 pm: |
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I've read that on a curve the most benefit is between 100 and 250 watts, after that the curve flattens out and the gain is negligible until you get to an ungodly amount of power well over a 1 KW. But I do not have the knowledge or the bookmark to really back me up. It’s just something I’ve read and can’t even quote accurately. |
Highlander
Advanced Member
Username: Highlander
Post Number: 559
Registered: 12-2001
| | Posted on Thursday, July 22, 2004 - 7:35 am: |
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Bob_p, that is my understanding as well, and it seems to bear out with my experience the last few years. I can see if I was into ham contests and stuff like that, 1500 watt legal limit amps for the HF ham bands might be nice, but for 11 meters, it is that first big jump from 4 watts to 100 or so that makes the biggest difference. |
Bob_p
Junior Member
Username: Bob_p
Post Number: 24
Registered: 7-2004
| | Posted on Thursday, July 22, 2004 - 1:03 pm: |
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Thanks Highlander I believe the biggest difference was between 4-100 but you gain a full 3 S units at 250 watts. The next three S unit was not gained at 500 watts it was more like 3KW. Like I said the Curve became very steep.
The antenna is helpful, and getting the highest DB gain performance is important, but getting it to 70 or 100 feet does not improve the performance. Unless your surrounded by obstacles I believe on 11 meters the most important thing was to achieve 30 feet or about a 11 meter’s in height. I do know the improved performance over that height was minimal but cannot remember the exact height. I suppose 50 feet wouldn’t hurt, but it’s not going to make a night and day difference unless your in a hole or surrounded by trees.
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Bruce
Senior Member
Username: Bruce
Post Number: 1395
Registered: 9-2003
| | Posted on Thursday, July 22, 2004 - 1:33 pm: |
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hummmmm
As a " ABOUT " formular
Distance (line of sight in miles) = ( square root )hight * 1.45
.......so.......
a 25 foot high antenna is 5 * 1.45 or 7.5 miles
Beyond that power will drop off fast because it will be beyond the horizon now higher power will fill in but only to a extent. I run 100 watts on most bands any more only invites problems. |
Geekster
Member
Username: Geekster
Post Number: 91
Registered: 6-2004
| | Posted on Friday, July 23, 2004 - 8:27 pm: |
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It depends on many factors. Frequency, antenna height, gain, earth conductivity, surroundings, etc. Ground wave is calculated much different than the sky wave, and a vertical antenna will be best for ground wave.
You also have to take in effect the resistance (atmosphere) to wave travel which decreases by an increase in frequency. Most frequencies above 100MHz pass thru the ionosphere unless sporatic E is taking place. That is why VHF and above is used for satelite comm.
After an antenna is high enough sky wave will be mostly generated.
Best book for reference is Fred Termans Radio Engineering Handbook circa 1943. Old book but very fascinating information about ground wave, attenuation (frequency), earths curvatures, and all the formulas.
You can also use the inverse power intensity formulas but you have to figure in for frequency variations with a few other formulas, and this formula assumes a perfect circle of radiation and is mostly used for 100MHz or higher frequencies, and radar.
HF waves are very unpredicatable and if skip propagations exist its even harder to determine range. Don't forget the Luxemburg Effect either.
Good Luck. |
Stickshift
Intermediate Member
Username: Stickshift
Post Number: 169
Registered: 7-2003
| | Posted on Monday, July 26, 2004 - 8:45 pm: |
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4 watts and a GOOD antenna will give you better results than all the power in the world and a junk antenna, aka dummy load. Why bother with anything else? Save the money from the amp and put towards something more useful. |
Pig040
Advanced Member
Username: Pig040
Post Number: 520
Registered: 7-2003
| | Posted on Tuesday, July 27, 2004 - 10:25 am: |
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4 watts would do the job if everyone else is using 4 watts. Unfortunately very few others are, so it wont. The dummy load is a good tool to use when checking your radio out. I agree that the antenna is the most overlooked important part of your system. |
Tech548
Moderator
Username: Tech548
Post Number: 177
Registered: 5-2004
| | Posted on Tuesday, July 27, 2004 - 10:43 pm: |
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Amen to that Pig040.
And as far as using linears for working DX goes, anything more than 200-250 watts is a waste of RF energy. What can be done with 1KW can also be done with 100 watts as long as the congestion isn't there.
If one feels that he/she needs 1KW to work DX, then that same he/she hasn't a clue what DXing is all about. A lesson is to be learned here from the ones that understand wave propagation, antenna design and/or building, and RF power multification. These guys are the real radio operators.
ANY of us can be CBers, but not all of us are real radio operators. Lonnie understands this. He, like many others here, knows how to use and work the available conditions in his favor. Example.... 6-8 watts into New Zealand. That wasn't a misprint or a feat certainly not unheard of. It's common-place for those that truely know how to "work" the available "conditions". It doesn't take massive RF power to do it.
Jeff. |
Wolverine
Intermediate Member
Username: Wolverine
Post Number: 203
Registered: 2-2003
| | Posted on Wednesday, July 28, 2004 - 5:05 am: |
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Tech 548, when you mentioned anything more than 200-250 watts is a waste of rf energy, are we talking average/rms watts or peak/pep watts?. Reason why I'm asking, is that most cber's that I know prefer a 500 watt peak amp, which translates into a solid 250 watt rms carrier, as opposed to a 125 watt amp that will swing 200-250 peak/pep watts. I do see that after 250 watts (3db), that you reach a point of diminishing where distance is concerned. So, are we talking rms or peak watts?? Thanks in advance.
Wolverine. |
Tech548
Moderator
Username: Tech548
Post Number: 179
Registered: 5-2004
| | Posted on Wednesday, July 28, 2004 - 5:12 pm: |
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Wolverine
Most CBers today are using PEP meters. If you were to take them away and in return give them a RMS meter, most would freak-out since they would see what their true RF power actually is. It would most likely be a big dissapointment to them. Besides that, the expensive RMS meters are out of most average CBers reach.
To get back to your question, I was refering to PEP wattage because that's the kind of meters that most CBers own. And speaking of RF power, you struck a note with me when you mentioned the magic number 500!! In my opinion, 500 watts can do just about anything. From there, you would have to come up with about 2KW just to see another S-Unit increase. That spells a waste of money and RF energy in my personal opinion.
Your friends that are using 500 watt linears are probably averaging anywhere from 150-300 watts in their "talk" power. And chances are, their 500 watt amplifiers aren't even breaking a sweat.
Jeff
Tech548 |
Wolverine
Intermediate Member
Username: Wolverine
Post Number: 204
Registered: 2-2003
| | Posted on Wednesday, July 28, 2004 - 8:23 pm: |
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Thanks Tech 548. I'm pushing about 380 to 410 watts on a good day. That's plenty enough rf power to suit my purposes. My friends use what they call "Hot boxes" (Amps with a built in driver or drivers). I've always preferred a straight 2 pill amp, or 4 pill amps. I'm leery about these boxes and that 1 driver pill dying on me, even though my friends swear by them. Although, if I was to be totally honest with myself which I loathe to admit, I might consider trying a 3 pill (500 watts peak) someday. Thanks again.
Wolverine. |
Crackerjack
Intermediate Member
Username: Crackerjack
Post Number: 162
Registered: 7-2004
| | Posted on Thursday, July 29, 2004 - 1:54 am: |
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Tech 548 is right, I run my KLV-400 on low power MOST of the time. |
Tech548
Moderator
Username: Tech548
Post Number: 181
Registered: 5-2004
| | Posted on Friday, July 30, 2004 - 4:28 pm: |
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The death of most linears is caused by heat build-up. This heat build-up usually comes from the linear being over-driven and/or prolonged usage without proper cooling.
Just because a given linear is capable of producing a maximum of (example) 500 watts, that doesn't mean that it has to be hammered into hard enough to constantly see that 500 watts show up on your RF power meter.
If it's just idling along at (another example) 200-250-300 watts, that darn thing will last you a very long time. The difference between 250 and 500 watts is only about 1/2 S-Unit...if even that. And that tiny bit of S-Unit difference isn't worth the destruction of a good 500 watt RF amplifier.
I bet there are some guys here that have been using the same linear for years and years without a bit of trouble. And I'm thinking the reason for that is because their linears are not taken to their maximum RF power limits but maybe rarely.
A general rule of thumb in the Ham world has always been, buy more linear than what you will ever expect to actually use. In otherwords, if you would be more than happy with 250 watts of power, then buy a 400-500 watt amplifier. That 250 watter won't last you too long if you constantly use all of it's available power because that's not what they were designed to do.
Burning up radios and RF linears by running them at their maximum does however have a plus side. It sure helps at keeping Copper Electronics in business. And for that we thank you.
If this post offended anyone, then I oppologize. It certainly wasn't meant to.
Jeff
Tech548 |
Bullet
Intermediate Member
Username: Bullet
Post Number: 359
Registered: 7-2003
| | Posted on Thursday, August 12, 2004 - 5:07 am: |
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sq root of hgt x 1.45.
30 feet or 5.47 x 1.45=(7.94) miles using this "on paper" method. should be extreamly easy to cover 8 mile radious @ 30 ft.
70ft or 8.36 x 1.45 = (12.13)miles using this formula thats half again the distance of the first stations coverage.
100ft or 10 x 1.45 = 14.5 miles or about twice the range of the first stations coverage.
those numbers seem really weak compared to the air miles being talked on 11 meters in this area anyway.
i talk nightly with only 2 watts carrier on my 11m colinear @ 68-70ft to a buddy thats 40 air miles away using a six element quad @110ft.
using the above we could talk (26.63) miles distance apart. but were 40 some and barefoot'n it.
point being height does make a differance in "reliable" "noncondition's" comunications.
i have a single antron at 30ft that barely makes the trip at 2 watts(weak and alot of white noise) |
Highlander
Advanced Member
Username: Highlander
Post Number: 578
Registered: 12-2001
| | Posted on Thursday, August 12, 2004 - 2:28 pm: |
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Then you get into VHF/UHF where height is everything...
The other day I worked a guy in a corporate jet on 146.520 FM. He was running 2 watts at 33,000 feet and was about 250 miles from me. At first I thought we were having the mother of all tropo openings, then I realized he was aeronautical mobile. Pretty neat! |
Patzerozero
Junior Member
Username: Patzerozero
Post Number: 46
Registered: 7-2004
| | Posted on Saturday, August 21, 2004 - 9:03 pm: |
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how did i miss this thread? maco V5/8 35' to tip w/ar3500 @135w on diamond sx100 peak talks anywhere 95% of time on ssb 27.455-27.655, same watts on am 26.835-a HEAVY DUTY skip freq, and i can make a fair amount of contacts, particularly those i talk to on a regular basis since late 70's since they're listening for me. mobile w/84"predator and 2-2290's driving 8-2879's, is definitely overkill on ssb, can do it mobile most of the time w/only 200w out. my am freq is where the power is needed mobile, hard to get a shooting star under the 10'5" RR trestle around the corner, so power it is. and even 1kw don't cut it sometimes when the competition is using that as a driver. |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 230
Registered: 7-2004
| | Posted on Sunday, August 22, 2004 - 12:04 am: |
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I honestly think getting the antenna to the 36 foot mark is the first major step.
As far as power goes for the last two years I ran a Cobra 148 GTL and Palomar 250 that did about 150 watts according to my PDC 600 and have what I think is a pretty impressive log book. |
Tech548
Moderator
Username: Tech548
Post Number: 259
Registered: 5-2004
| | Posted on Monday, August 23, 2004 - 5:15 pm: |
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You couldn't be more correct Bob.
Having the antenna feedpoint at 36' or more is definately a plus my friend!!!
Jeff
Tech548 |
Bob_p
Intermediate Member
Username: Bob_p
Post Number: 250
Registered: 7-2004
| | Posted on Tuesday, August 24, 2004 - 5:27 pm: |
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Jeff thanks I was pretty sure those two points were the most important in terms of DX anyway.
But I recently moved my antenna from it's place at 38 about feet because I was afraid a large branch from a tree might be dangerous to the antenna. It was also within 7 and 10 feet of the trunks of two massive Lodge Pole pine trees, and I mean huge. Plus it was sticking up above the houose on nearly 20 feet of free standing mast pipe, and though the A-99 stood there for two years. When I put the I-Max up I was concerned that even if I took 5 foot off it would be near 15 feet of free standing mast pipe. So I put it in a tri-pod on a 10 foot section of mast pipe on the top of the house. So I'm now at 30 feet or so. I really hated loosing that 38 feet or so, but it even looks sketchy with only about 7 feet or so of mast pipe sticking above the tri-pod. |
