Radio With Amp Questions

[thetez]

i dont know if it is or not, and i wont know till it arrives at my house... found it on some local "Sell your garbage" site.... a guy said he had a pre amp for 20 bucks, new in the box... didnt give too much info, dont even remeber the site, but i did the research, and found out well what i said so far.... but it does sound like what your talking about

[markthetrucker]

K7AAB is giving you great advise. I used to talk a lot on the CB before trucking and Ham operators will always tell you....antenna, antenna, antenna.

I used to use a wilson 1000 mag mount with a ground plane kit. awesome antenna. I also had a Cobra 19 and I got out at least 20 miles. if you want to get wattage get a better radio like the 2970 or a good connex hp but they will cost you around 500 bucks. I can get about 60 miles with the setup I have now.
Plus with an amp...they don't help you HEAR the incoming transmission so...whats the point. another reason I like the 2970 great RF is just as important as getting to them.

[thetez]

Well i just installed my new 4ft FGT Wilson Silver Load Antenna, With a great belden coax, and am currently using my cobra 19.... Only untill the cobra 29 that has been tuned arrives... And wow, this antenna is amazing... i thought the magnet mount one i had was good, .... and it was, but WOW i was amaizied at how much further i could hear/talk. Cant wait till my 29 gets here.

Oh, and the amp i am getting, isnt a linear amp, its a ... an "incoming signal amp" more or less..

[SpeedyWho]

Take sure to check your SWR's if your not tuned right it willl not matter how much power your using

[thetez]

I already tuned it up, and boy was it an easy tune...

and like ive said, im not boosting my power to get out... Im getting a different type of amp...

[thetez]

Has anyone ever heard of these? :CB Radio Antenna Linear Signal Booster - made by WMC

it looks a lot like a 3" long tube with the bolt bottom on the bottom.. with a coax cable coming out the top....

if i can get permission from a board admin to post a link to the picture i will do that

[thetez]

that's it....

[thetez]

Originally Posted by BobC

The whole thing is not something you should try at home.
It takes a bit of bench hardware to get the adjustments correct.

A 40 watt amplifier is useless & isn't worth the effort of hooking up.
If you're not starting out with a minimum of 150-200 you're wasting your time & effort.

Stay away from the units called "modulators".
These are a bastardized version of an amplifier.
Their main purpose is to distort the waveform to make it appear louder locally.
In affect, it does make you a bit "louder" but at the expense of everyone around you on another channel.
You will be causing a fair amount of bleedover onto surrounding channels.

The idea of "matching" your radio to the amp is simply making sure that at any given power setting, your radio does not overdrive the amplifier & get distorted.

Another benefit of "matching" ensures that the amplifier presents a good swr to the radio when switched in.
You can have a good antenna swr but when the amp kicks in you're really transmitting into another transistor & a bunch or wires to a relay & back out.
All that extra lead length can create a poor swr for the radio.

The actual "tuning work" can take a while because you need to create the proper setup for testing & the radio needs to be set first.

Generally, you set the radio for 100% max modulation.
Once set, you continue injecting a tone or two into the radio mic input at 100% mod.
You then increase of decrease the radio's carrier power until the amplifier's output is on the verge of "flat topping"/compression.
Back it off just a little from there.

This ensures that even at the highest power setting of the amp, you will not overdrive the amp & create a bunch of splatter on other channels & the amp sounds "clean" on the channel you're using.

If you intend to use the amp on ssb as well, there's a bit more tuning to be done.
SSB requires the best tuning because if there's any distortion it will show up on SSB.

Switch your test radio to SSB, ptt & inject a tone or a pair of tones as are commonly used.

Increase or decrease the radio's "alc" adjustment so that the amp just begins to distort (flat top) & back off a little from there.

Now, no matter what setting the amp is on, you cannot overdrive it.

There's a last adjustment for ssb amps & that is the bias adjustment. This is usually not adjustable & requires a few trial & error parts changes in the amp.

The same bias(predominantly for ssb but effects AM as well) adjustments are variable inside the radio & they must be set correctly before performin the amplifer tuning.

A final checek to make sure the swr is good going into the amp & thru the amp when off.

It's tuned. However it's only tuned for the combination of that radio & that amp.
You might get away with using a different radio as long as the next one shows similar output power as the original.

WOW!! ive come along way in knowledge and my set up since then... a lot of it is probably due to a lot of you guys and my other research, so thanks!

But i do a lot of side band talking, and with all this skip going on, you can not talk with the low power a CB puts out... i can hear the local guys as well as guys from the other side of the country alaska, and canada, but they cant hear me, not even the local guys, i was thinking about putting an amp in my 4 wheeler.

dont know yet, im looking at a couple diffrent 200 or 300 watt ones or around there....

but if i installed it i would not want to mess it up, i was curious if someone could go into more detail about what was said, more of a "how to do those steps" type of thing...

who knows in the end i will probably swallow some pride and let the tech do it :-/