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Exman
New member
Username: Exman
Post Number: 1
Registered: 5-2005
| | Posted on Sunday, May 29, 2005 - 11:12 pm: | 
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First sorry for the long post but best to tell whole story.
I've been out of radio for 20+yrs and just picked it back up, wanted a killer system to put in my fiberglass 27' R.V. I talked to the copper people and bought a 95t was told it would do 150w barefoot.- Love it!!
I installed it and went on, I had a high swr with my K-40 and no meter so I stopped along the way at a CB shop to see about my high swr problem after adding a ground wire from ant. base to a top rail aprox 20' long swr was down to 1.5 or better. After that the tech talked me into letting him peak it out, so he went to work on removing the mod limiter and tweaked a few things, spread some coils, all that stuff when he was done it did 15DK swing to 160 with a 636L mic he also added. At this time you could not adjust RF, no matter what it swung to 160. OK so I went on. Thinking was that the right thing to do?
About a week later I came across a pre Tesas Star 400 and was told it would do 800w, I did want to blow smoke so I bought a good meter read all kinds of info here in the forums- Lots of great info!!! I set my radio to DK 3w low/ 100w high, still swings from 4 to 160. Ok I was told this amp could handle it great, I hooked it up and it did do 800 when I pushed in the am button and keyed I did blow smoke, from the 500w ant coil and R-4 of the amp -oops! I was told by the above tech to not run with the am or ssb button in or this could happen. Why I don't know.
I replaced my ant with a wilson 1000 got the swr below 2 with no amp at 100w, hooked up the amp and swr was high with radio DK3, amp DK'ed 300 and swung to 850 with mod.
After playing with my new toy I again blew smoke this time R-23 of amp, *@#$% I took out the amp for repairs, put the radio back to 4DK swings to 150+ and set high to 100w, added a maco-91 ant matcher to correct my swr to 1.1
Before I turn more money to smoke could somebody set me straight on this, seems like so much information here but the few problems I'm having are making me not so happy. |
Road_warrior
Advanced Member
Username: Road_warrior
Post Number: 606
Registered: 7-2004
| | Posted on Sunday, May 29, 2005 - 11:51 pm: |
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I would have never left that Tech clip
stuff out of your radio. I usually run
2-3 watt DEAD-KEY with no more than
8-10 watts of swing going into an Amp. (AM)
Unless it's a high drive amp.
Your better off having a regular radio
with a large AMP behind it.
The 95T has a built in amp, so, you don't
need to use one or can be used to kick
a really high drive amp, but, not an Amp
made to take only 4 watts or so...
JIM/ PA/ CEF 375
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Road_warrior
Advanced Member
Username: Road_warrior
Post Number: 607
Registered: 7-2004
| | Posted on Monday, May 30, 2005 - 12:14 am: |
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The thing to remember about power.
After you reach 100 watts of power it
then takes 200 watts to see any difference
in signal strength.
To see much difference from 200 watts it
takes 400 watts, then 800 watts and so on.
100-200 watts is plenty of power.
JIM/ PA/ CEF 375 |
Patzerozero
Advanced Member
Username: Patzerozero
Post Number: 842
Registered: 7-2004
| | Posted on Monday, May 30, 2005 - 12:14 am: |
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that sounds like what the CUSTOMER does when i tell them NOT to!!!
the 95t is best suited to drive an 8 transistor amp, such as a texas star dx1600, or even a 1200. a texas star dx 400 will ONLY do about 325 watts as it has 4-80 watt transistors. it will ONLY handle the input of a stock cb, 4 watts dead key & maybe 12-15 swing.
the most RELIABLE solution is to upgrade the amp & antenna to match the radio, or replace the radio with 1 without any built in amplifier section, or just use the 95t as is with 150 watts.
make sure the antenna matcher will handle the wattage or it'll need replacing soon, too. better yet, work to get the swr's to less then 1.5:1 without the tuner. a tuner is just tricking the radio into thinking the antenna is properly matched, it's still not resonant on the proper freq & though all your power is going out, it's not going as efficiently as if the ANTENNA itself was tuned correctly.
ain't smoke neat!
10 ohm smoke means you got MAXIMUM output from the amp!!! once, at least!! |
Chillydog
Junior Member
Username: Chillydog
Post Number: 14
Registered: 12-2003
| | Posted on Monday, May 30, 2005 - 1:31 am: |
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Exman,
My first impression from reading your message is that you're moving too fast!
First of all, regarding the reasons for putting a radio in an RV. I would assume you would want a radio for traffic information while on the road, chatting with those you may be travelling with, finding your way around an RV park, and similar general communication uses. The 95T is beyond adequate for that. A Cobra 19 is fine for those situations!
Even with your previous experience, a 95T has a number of features and capabilities that would take time to explore and really understand. It also has much more power than most users utilize. In other words, it's a bit more radio than used for typical RV applications. If you have interest in other radio uses, wait a bit. I'll cover them later.
That said, you've expressed a desire to "blow smoke." If by that you mean burning up electronic equipment, you're already successful! Or, if blowing smoke means that you'd like to transmit a nasty, spectrum trashing signal, one with extreme distortion that really doesn't communicate and makes use of the six (or more) adjacent channels on either side of your chosen frequency unuseable, you're on the right track.
Here's what I mean by that. You've made reference to a 4 watt carrier ("dead key") and a 150 watt peak ("swing") signal. That's a dirty signal; it represents a transmitter overmodulated by a factor of almost 10. That's a very distorted output!
For the most part, if you're running a dead key of 4 watts, your swing should max out at 16 watts. If your swing is 150 watts, your dead key should be around 37 watts. Those numbers represent a 4:1 peak modulated to RMS carrier ratio. Modulation greater than those parameters is excessive and results in bad sounding, distorted audio and "splatter" into channels outside of your desired frequency.
You mention that you've allowed your radio to be manhandled by a radio rapist who claims to be a tech, who has removed the mod limiter, spread some coils, and God knows what else. At least the 636 isn't a power mike! (Is it? I hope not!) A power mike on a butchered radio just makes everything worse!
The modulation limiter is designed to allow maximum talk-power without overmodulation. Disabling it can result in terrible operation that may not be apparent on the channel you are using. The coils (inductors) in a radio serve many functions, including reducing spurious, off-frequency operation. "Spreading" some coils for the most part means that the moron who did so has increased your transmitted harmonic output. That would cause much of the power your radio is emitting to fall at 54 MHZ or so, 82 MHz, whatever; way outside the recieve passband of anyone in the CB bands! Wasted power!
Now, regarding the amp. You are massively overdriving it. With a four-pill 2290 amp (which I understand the Texas Star 400 to be) a drive of up to 30 watts peak and a corresponding carrier is probably plenty. With 160 watts input, you're guaranteed smoke. With your radio having no modulation limiting and ineffective harmonic suppression, it's even worse!
My question is why bother with an amp at all? The 95T has plenty of output. Unless, of course, you want to mess with other operators, "squishing" them, interfering with their communications, "owning" the airwaves. If that's the case, please continue using your distorted 95T and overdriving your amp; with luck, you might get a few seconds of transmit in before you blow your rig. Then the rest of us can continue to share the radio spectrum.
If however, you want to have a good sounding radio, use it responsibly, and have a good time not only talking on the road and in the park, but communicating all over the world, take your radio to a qualified, responsible tech with the correct equipment. (Someone at Copper would be great!) Have your radio returned to correct operating conditon. If you don't know how to use a SWR meter or correctly install an antenna on an RV, find someone who does. With a properly adjusted 95T and a good install, you will be able to get out and talk to people everywhere.
Forget about the amp for a while. There's no point in a four-pill amp with a 95T; it won't make much, if any, difference in your ability to get out.
You may not be happy with my never-to-be-humble comments, but you've already stated you're not happy with your current operation. Give up blowing smoke. Don't worry about how many watts you're putting out; strive to put out the cleanest and clearest signal you can. Realize that much of what you read in forums is urban legend and ignorance.
Heck, don't even take what I have to say as fact. Question it, research it, learn for yourself. There's a lot of bull out there. You'll find many who swear by cutting limiters. And sometimes it may appear to help. But far to often a cut limiter results in poor quality audio and/or interference to other channels. There are endless debates about which microphone is "best," which antenna is "best," which amp is "best," which radio is "loudest." Do you know what? There is no "best!" And "loudest" doesn't always mean good. The best answer to all of those issues is "it depends!"
I could go on and on, but my bottom line is this. You are already experiencing the effects of incorrect information. You've spent a good amount of money that has gone up in smoke! Find another tech, move more deliberately, and you'll get a lot more for your money and have more fun.
Very Best Regards,
Bob
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Alsworld
Advanced Member
Username: Alsworld
Post Number: 918
Registered: 1-2002
| | Posted on Monday, May 30, 2005 - 3:51 am: |
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Exman,
I just installed an antenna on a friend of mine's RV. Fiberglass RV's and antennas are hard to match. Throw in an amp and the situation gets very complicated.
Not impossible, but there are many variables. Fiberglass RV's are extremely hard to match an antenna and amp with a radio. Ground plane just isn't there.
Removing a mod limiter fromn your radio has little to do with the match, but a super dumb move to do to a 95T. No bad on you, but your "tech" should be shot without mercy. 10 meter radios are not like a typical CB radio. Removing mod limiters on these putting out this much power should have been your first clue, but I understand time has not been in your favor.
No offense, but your "tech" worked at a truckstop and has butchered your radio. You lose. Sad but true. Welcome to the "I just got screwed and paid for it" club.
Bottom line, fiberglass RV's are not designed to run amps and now you must pay twice the amount to fix your radio.
Sorry for the truth and I know it hurts, but it is what it is. I hate to be the bearer of bad news.
Alsworld
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Justlou
Junior Member
Username: Justlou
Post Number: 29
Registered: 3-2005
| | Posted on Monday, May 30, 2005 - 11:00 am: |
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No, No, No.... A great radio like the 95T ruined with a golden screwdriver. *sigh* Consider contacting "Galaxy Radio Repair" about getting your radio restored to the way it should be. |
Heavyweight
New member
Username: Heavyweight
Post Number: 6
Registered: 11-2004
| | Posted on Monday, May 30, 2005 - 5:06 pm: |
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Why cant you find a good place to mount your antenna on that rv like on one of the rails that run across the top of the roof or maybe along the rear of the rv.Then run a ground wire from the mount to the frame to get the best possible ground and you should no problems with swr.
If you really want to walk tall in a sea of mudducks then have your radio tuned by someone who knows what they are doing then buy one of the larger amps like dave made,x force,scullcraker,ampower or whats called a comp box something that your 95t would drive well but not over drive,i would try to stay with a 6 or 8 pill box.once your radio is tuned the way it should be and you get your swr down to where they should be you should be very loud and very clear.I know that my steup,95t,8 pill dave and a 102 steel whip works very good together and no it does not sound like some of the overdriven P.O.S's that you hear on ch6 or 26. |
Exman
New member
Username: Exman
Post Number: 2
Registered: 5-2005
| | Posted on Monday, May 30, 2005 - 10:50 pm: |
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Lots of GREAT info, your years of DXing has given all of you the insight I don't have on this subject, seems like everbody has a different view on this but that is why I posted this thank you all.
The reason for installing in my RV, due to the fact that I travel the US working for Fire Departments handling hazardous mats. and live in it 5 days a week or more, it is my rolling hotel room. Also I've had 2 heart attacks and I travel to where I have no cell phone coverage and I thought this would be the best way to reach help if needed, bought the radio for just that reason, but after that I caught the same bug all of you have now, and I too want to become a HAM just like you. So I picked up a hobby I put down years ago.
I want the best, clean, clear & loud not a bleader I to want to keep the spectrum clean but also want to have a great system and everybody gets caught up in bigger is better and you can never have too much I just want a system that demands respect.
As far as the tech cutting up my rig the only cut or removal was the mod limiter but I was told to run the mic gain @ 1/2 to avoid over modulation. other stuff was just tweaked. I can set my DK with the knob to anything from 4 to 100 does this mean I'm not spatting or distorted when swinging to 160 with DK of 100 lets say?
Chillydog you are right there is a lot of bull out there thats why I asked because so far I'm still looking for the correct solution for the killer system depending on my installed equipment
I'm sure everbody already has the BEST I just want one too.
As far swr and installation problem- the RV has a fiberglass flat top and fiberglass sides that are joined at a 90 with a small alum. rail aprox. 1 1/2" wide that runs from front to back hardly any other metal up there at all. There is no rail going across. I mounted a 1/4" thick small bracket out over the drivers door on the roof and installed the wilson trunk lip mount to this bracket the coil extends past the side of the rv and only road below it. The base is 10 1/2 feet in the air. so far I can only get to a 2 1/2 swr at 100 watts DK. I have resorted to a 300w ant. matcher and now get a 1.1 at the radio and I can also hear better this way. Sounds like a 102" wip is the way to go but no way ti install on my rig and if installed on the roof would wrap around the traffic lights as I went under them I aready smack stuff with the wilson.
Is 800 watts not better than 160? So Maybe I really don't need the amp. Is bigger better?
I have been listening to some of you on the CEF net on sundays and about to particapate as I have joined, looking foward to talking with you all and I want to be a part of the family of HAMS as I work to join your ranks I'm just getting a rough start. -Still thinking about putting the amp back in once repaired maybe...
But this time its gonna be RIGHT! Dont want a ch 6 radio.
pat-wish you were closer maybe when Im in nyc sometime you could smack me in the back of the head, I oversee systems at TLC.
bob-I'm with you man- thats where I'm tring to get.
To all: as I travel for a living in an RV someday I may be in your town-I'll buy lunch! (don't know what I'll do when I retire)
Please continue to feed me the RIGHT INFO.
73's to all
exman cef576 |
Brewdirect
Intermediate Member
Username: Brewdirect
Post Number: 107
Registered: 7-2004
| | Posted on Tuesday, May 31, 2005 - 6:29 pm: |
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Wow...get that radio to a "good" technician and have it restored to it's original state.
Need a much lower deadkey for that amp.
Secondly....I agree that you are moving way too fast man. That 95T with a good antenna should have you talking locally with no problem and you should also be able to shoot some good skip as well.
Adding that amp to that setup is not really needed, and if you are gonna add it you'll need to lower the input.
That's also a lot of watts to be running into an antenna system that doesn't have the best grounding system available. A fiberglass RV isn't great for grounding...you may get a lot of stray RF floating around...wouldn't be keying that baby up for long periods of time with my family in the RV.
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Alsworld
Advanced Member
Username: Alsworld
Post Number: 921
Registered: 1-2002
| | Posted on Tuesday, May 31, 2005 - 10:28 pm: |
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That 95T is an awesome radio, but it will take one heck of an amp at the swing it has. The Texas Star 400 is nowhere near designed to take that many watts. Properly driven, it's a great amp. But that 95T is way too much radio for it.
As said above, if sticking with the Texas Star brand, go with the sweet 16. But that radio can drive some other amps very well.
Look into the MagnaForce 600 (minimum), or MagnaForce 1000. Those will handle the drive of your radio and sound great. Yes, it's bordering into the competition world of amps, but they will take the 95T with ease. I mention this line because it has the biasing that will work on SSB as well and sound good.
Now keep in mind that if you were to run this setup, other problems occur. What will now be your weak spot? Can your coax handle this much power? Is your antenna matcher designed to withstand watts peaking around 1000+? With such a short antenna, can the antenna itself hold it? That is assuming your alternator can support the amperage draw. See what I mean?
To keep things simple with what you have, buy yourself a MagnaForce 600 or 1000, fuse it and feed it well with quality power cable, and give it a shot. At least you won't blow your amp anymore.
I still believe the lack of groundplane will show itself somewhere.
Look forward to contacting you on the Sunday Nets. And for what it's worth, your 95T has plenty of power itself.
Alsworld |
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