CB Radio microphones

[eccerr0r]

Ok, this really isn't a true "audio" equipment but, well, is still very audible...

Just wondering how often people have heard of microphones going bad. I have two CB's that have bad microphones and did not know until testing them with each other... and then trying to hook up a speaker to the PA output.

Very strange IMHO, but maybe it shouldn't be that strange? Is this common?

[stj]

Re: CB Radio microphones

they can fail,also the cable can break or break in the plug.
some contain electronics like compressors or amplifiers too.

[kc8adu]

Re: CB Radio microphones

seen plenty of the older dynamic elements open.
back when a cb was something one would pay to have repaired i saw a lot of mic failures.
cords,plugs,wiring errors,even dirty ptt switch.
second was idiot "tune ups" and screwdriver drift.
dont do many cb repairs any more but still get a few.mostly old school quality units like this cobra.

[michael dranfield]

Re: CB Radio microphones

This post takes me back to the summer of 1979 when I was just 15 , here in the UK some truck driver brought a load of CB radios over from the states and before you knew it all the UK had gone CB radio crazy, in the UK it was of course illegal to transmit on the 27Mhz AM and SSB and thats what made it so exciting doing something illegal, but by the early 1980 we were in the midst of some sort of sunspot and and radio waves , Skip, were coming over to the UK from the states pushing close on S9 so it was easier to hear someone in the states than it was the breakers down the road !
I got big into repairing CB radios, the demand was massive, the most common problems were the 2SC2078 PA transistor burning out on 4 watt rigs and the audio output chip TA7205AP which also doubled up as the PA stage modulator, I still have all my CB stuff here , Tristar 747 amongst many other rigs, in uk when they legalized CB radio in 1981 it was on FM which meant
no DX ing so by 1983 CB had died a death.

[vinceroger69]

Re: CB Radio microphones

This post takes me back to the summer of 1979 when I was just 15 , here in the UK some truck driver brought a load of CB radios over from the states and before you knew it all the UK had gone CB radio crazy, in the UK it was of course illegal to transmit on the 27Mhz AM and SSB and thats what made it so exciting doing something illegal, but by the early 1980 we were in the midst of some sort of sunspot and and radio waves , Skip, were coming over to the UK from the states pushing close on S9 so it was easier to hear someone in the states than it was the breakers down the road !
I got big into repairing CB radios, the demand was massive, the most common problems were the 2SC2078 PA transistor burning out on 4 watt rigs and the audio output chip TA7205AP which also doubled up as the PA stage modulator, I still have all my CB stuff here , Tristar 747 amongst many other rigs, in uk when they legalized CB radio in 1981 it was on FM which meant
no DX ing so by 1983 CB had died a death.

This is roughly the same time i started experirmenting in cb radios my first set was a amstrad 901 with the fairy lights instead of a meter i also had a thunderpole mk2 on my house wall the neighbours didnt like it lol as interfired with there tvs. I used to repair a few for mates mainly blown tda7205ap also wrong polarity repairs/broke mike wires etc but never got into the tuning side of things.

[michael dranfield]

Re: CB Radio microphones

This is what more than 40 years of not throwing anything away does for you !
I have the service manual for the 901 somewhere but cant just lay my hands on it.

[steviewonder]

Re: CB Radio microphones

Had many a happy hour repairing rigs,My first one was a Rotel RVC220, £20 brand new,back in the day...1982-ish.The 901 wasn't actually that bad,compared to commtel,fidelity 1000 and their clones..Eurosonic made a few truly awful efforts-Audioline/Uniden were considered the best,and the Cobra 148gtldx came from the same family...Ahh..Multimode 2-gawd,wasn't they awful? Ham jumbo was the same thing in a flash cabinet with built in psu and swr meter..As michael says, those 2sc2078's were crap,think I used to swap those for 2sc2116 or 2sc1909 if i remember correctly..microphones generally had the wires hanging out the plug,tarnished contacts on the PTT switch etc..Don't recall too many O/C coils though..

[steviewonder]

Re: CB Radio microphones

I did have a soft spot for the cheesy performance of the Maxcom 21E-probably because it was tiny,with fairylights-and one of the midland ones,that came with it's own case,battery pack and huge pull up aerial!

[stj]

Re: CB Radio microphones

i had a radio-shack 40channel "handheld" that looked like something you would use on the battlefield in vietnam it was so big!!

[michael dranfield]

Re: CB Radio microphones

Correct me if I'm wrong but did the states have ,22 channels when CB radio was introduced there ? In the UK we first had 40 , then 80 then USB and then LSB .

[stj]

Re: CB Radio microphones

http://ukspec.tripod.com/rf/handheld.html

[vinceroger69]

Re: CB Radio microphones

I did have a soft spot for the cheesy performance of the Maxcom 21E-probably because it was tiny,with fairylights-and one of the midland ones,that came with it's own case,battery pack and huge pull up aerial!

I also had a maxcom it was 20e seemed a good little set leant it to a mate never got it back.

[Hondaman]

Re: CB Radio microphones

At first, the USA had 23 channels. Then 40 later on. We are still at 40 channels to this day.

[vinceroger69]

Re: CB Radio microphones

in the uk the cb scene seems to of finished very rarely see any cars with aeriels on truck drivers do seem to still use them but i guess on the 80ch set ups

[stj]

Re: CB Radio microphones

it's a mix of 27MHz and probably illegal stuff and PMR 446MHz handhelds - also usually illegal because people use 5w radio's when the limit is 500mw

[michael dranfield]

Re: CB Radio microphones

http://ukspec.tripod.com/rf/handheld.html

23 Channels pre 1977 , I was nearly right .

[michael dranfield]

Re: CB Radio microphones

it's a mix of 27MHz and probably illegal stuff and PMR 446MHz handhelds - also usually illegal because people use 5w radio's when the limit is 500mw

500MW ? we power mad running huge linear amps , here is my old patch lead with an double A battery for comparison, the cable is RG8 and somewhere but I cant just lay my hands on it ,I have a newspaper cutting of the first person in my town to be busted for running a linear amp as he lived in a block of flats and when on TX it wiped everybody's TV reception out, the fine was something like £100 which in today's money would be perhaps worth £1,000 .

[stj]

Re: CB Radio microphones

yea, a friend had a 250w burner in his van, but not at 446MHz!!!!!