A question about CB Radio

[Richard Crowley]

There's probably more than $10 worth or parts in them that I can use. Just the channel select switch alone could be useful and probably cost me more if I were to buy one.

At some point in their evolution (clearly long before digital frequency synthesis), they used an elaborate array of quartz crystals and a weird sequence in the channel select switch to create all 23 (or later 40) channel frequencies.  I got the impression that many of the channel selector switches were not simply SP23T or even BCD switches.  So even the channel switch might be an oddball component. 

Rather amazing the things that we did mechanically back then are considered antique and obsolete today.

[W9GFO]

Which might explain why truckers are one of the few groups that still use CB

I have mixed feelings about CBs. Back in the late '70s and early 80s we were quite active in REACT which was a club that used CBs for monitoring channel 9 for emergencies as well as other disaster preparedness things. This was in rural Nebraska. I started trucking in '88 or '89. The CB was very useful, but there was a lot of "trash talk". When I quit trucking about ten years ago CB usage was still valuable for communicating but the ratio of trash talk to civil communication was dismal. The huge advantage that CB has is that it is like one big party line. If you need some information you simply ask and chances are good that someone will respond. Can't do that with a cel phone.

What I find disappointing is that the trash talk has discouraged many from monitoring the CB, so the likelihood of getting a response is nowhere near as good as it used to be in the good ole days, which is a shame.

[McBryce]

I had one of those handheld ones when I was 10. Took a whole bunch of double A's had a ridiculous long 6' antenna, and I could never talk to anyone on it. I think it was only three watts.

Now the CB is garbage, the people just yell racial obscenities to each other in this weird fake southern accent, trying to out stupid each other. The epitome of a white trash Trump voter. They also run some stupid 100 watt amplifiers so you couldn't use a four watt radio if you wanted to, they just key over you.

I bought that radio at service merchandise and to "upgrade" the radio I brought it back where the sales man plugged it in to see if it was working; with the wrong polarity and blew it up, but then blamed it as defective and gave me credit towards a new cobra CB.

Yes, it has a 6 foot whip antenna with a closed coil in the middle, and it takes 8x AA Batteries which don't last very long if hit the transmit button (Possible Bateroo test candidate?). I left it on each time I was at my workbench this week and not a single transmission was received, so it definitely looks like nothing is happening around here. I'll scrap them for parts and find out if the channel select switch is really some mechanical wonder or whether I could use it for something else.

McBryce.

[CJay]

It's a mix of all sorts of things, CB in the UK was really popular when there was an element of 'sticking it to the man' but legalisation gave it a huge boost, tens of thousands of people  bought radios and within a year an awful lot of them were in cupboards, lofts, sheds or on the tip.

It declined from there with the rise of mobile phones and the 'net, in the UK telephones were *expensive* back in those days because there was one state provider and no competition, you weren't allowed to use your own equipment on their network, it was a criminal offence and you had to be rich to have a second line just for social use so CB was a cheap way to communicate between friends in your town, nowadays, messaging services like Whatsapp etc. are the favoured way for groups to chat and offer privacy and all the other benefits of a 'net messaging service.

The massive boost given to mobile phones by SMS was a big reason why people didn't take up CB, why bother waiting for your mate to be on air when you could text him any time, plus the rather naff image of American truckers from the 70s (think Convoy) and CB, radio in general, has become a bit of a joke to the general public nowadays.

I still listen in to CB occasionally (usually only when repairing one) but if there's anyone to listen to they're usually drunk, stoned, swearing at someone, selling drugs or some combination of, it's not really worth the effort.

These days I prefer to spend my radio time tinkering with and building things for ham bands or repairing things for people, gives me far more enjoyment.

[CJay]

Yes, it has a 6 foot whip antenna with a closed coil in the middle, and it takes 8x AA Batteries which don't last very long if hit the transmit button (Possible Bateroo test candidate?). I left it on each time I was at my workbench this week and not a single transmission was received, so it definitely looks like nothing is happening around here. I'll scrap them for parts and find out if the channel select switch is really some mechanical wonder or whether I could use it for something else.

McBryce.

If you want a 'straight' channel change with BCD coded outputs you're probably going to be out of luck, even the UK ones which had channels with no 'gaps' or hops mostly used an odd coding method but there were some UK radios which used sequential binary and one that (I think) used sequential BCD, if you have a use for one I have some here and could post you one for the cost of P&P?

I'd be interested to see the guts of both radios as I can't find much or any information about either so if you can spare the time to take a couple of board pics that'd be great.

Shame to scrap them, especially if the handheld is in good condition but...

[McBryce]

I'll post some pictures at the weekend when I have time. I've no current use for the channel select switches at the moment. I'm not specifically looking for them, I'd just keep these ones in case I have some use for them in the future.

If you are interested in having either unit (for use or for parts) make an offer.

McBryce.

[CJay]

Sadly postage would make it far too expensive and as you've already said, they're cheap enough that they're worth more for parts than any offer I'd make.

Shame to scrap them but as you've discovered, there's not much use for them other than as a curiosity (and they're likely illegal to use anyway) or parts.

[Codebird]

Rather amazing the things that we did mechanically back then are considered antique and obsolete today.

I have in my collection of parts a PWM power controller from an old microwave oven. It's purely mechanical in operation - a combination of microswitch, cam-tracker offset by the control slider, and a very unusually shaped cam. It generates a fixed-frequency PWM signal with an adjustable duty cycle from 0 to 100%.

[McBryce]

Ok, here's a few Analogue circuitry pR0n pics from the devices. Sorry for the crap lighting, I only get to really use my lab at the weekend.

First the TRC-427. The last picture is a close-up of the channel selector footprint. Looks like it is something exotic with multiple layers of switches.

McBryce.

[McBryce]

And the Handheld device. Unfortunately this is one of those devices that requires desoldering of components and jump wires to get inside properly.

McBryce.

[Lord of nothing]

PMR at 446KHz came as a replacement for non licensed amateurs.

you mean Mhzl. 
Haha and there are a lot of people with China Radios aka Baofengs. 
Worker on the Construction side, Kids, Babyphones,... thats why I switched to some Digi with more output fun. 

In some areas people have setup relay networks.

Who is by the European Law illegal. What i rember the law say "for mobile use only". That mean your the Repeater is not in a moving Car your get screwed up.

I see more activity on Freenet

Who isnt free in the rest of Europe. 

in the UK telephones were *expensive* back in those days because there was one state provider and no competition, you weren't allowed to use your own equipment on their network, it was a criminal offence and you had to be rich to have a second line

The same here in Austria. In the Past you had an 1/4 Line or worse a 1/8 Line that mean 4 or 8 Phones share one Telephone line no not in the Apartment, the hole Apartment building share one line!!!

So CB ist still in use more SSB I would say. <12W legal is quite nice.

I have a huge Problem with the ffuu..... Powerline Adapter the Send from ~2Mhz to 30Mhz. I could not get any clear Signal.

[madires]

In some areas people have setup relay networks.

Who is by the European Law illegal. What i rember the law say "for mobile use only". That mean your the Repeater is not in a moving Car your get screwed up.

Please see https://www.bundesnetzagentur.de/DE/Sachgebiete/Telekommunikation/Unternehmen_Institutionen/Frequenzen/SpezielleAnwendungen/CB-Funk/CBFunk-node.html and read CB-Funk Allgemeinzuteilung (German text).

[Lord of nothing]

PMR446 not CB.

[james_s]

Well you've got at least two of them, you could give one to a friend and use it to chat just for fun. If there's so little activity on the air you're not likely to have to share the band with anyone else.

[Lord of nothing]

  He can use it only when nobody use Powerline and other stuff there.

[madires]

PMR446 not CB.

Gateways are also allowed for Freenet and PMR in Germany.

[Lord of nothing]

i dont care are about Freenet.

http://www.erodocdb.dk/docs/doc98/official/pdf/eccdec1505.pdf

Check the official German speaking Documents.
For Austria: https://www.bmvit.gv.at/ofb/marktueberwachung/fsb/funkschnittstellen/fsbln.pdf

[Howardlong]

As we seem to be reminiscing....

I remember getting a legal rig soon after CB was legalised in the UK. For protectionist reasons, the UK gov decided on an incompatible FM system on 27MHz, also slightly offset from the AM channels so it meant a diferent PLL chip would be needed.

There was also a 900MHz band, but I don't know anyone who used that.

ISTR we needed to purchase a licence too.

A few months later I took my ham test, and other than very very occasional listening, I've never bothered with CB again.

Many folks used CB as a stepping stone to getting a ham licence in the UK back then, I am sure there was a similar influx in other countries as they introduced it.

[Lord of nothing]

There was also a 900MHz band, but I don't know anyone who used that.

GSM Phones?

[Howardlong]

There was also a 900MHz band, but I don't know anyone who used that.

GSM Phones?

It's not just GSM phones around 900MHz. The UK 934MHz CB band lasted until 1999.

[CJay]

As we seem to be reminiscing....

I remember getting a legal rig soon after CB was legalised in the UK. For protectionist reasons, the UK gov decided on an incompatible FM system on 27MHz, also slightly offset from the AM channels so it meant a diferent PLL chip would be needed.

I'd love to know the full reason for that offset, I've heard various stories about it, including incompetence and civil servants getting mixed up with VHF channel spacings.

There was also a 900MHz band, but I don't know anyone who used that.

ISTR we needed to purchase a licence too.

There was indeed, I knew nobody until recently when I was shown a full 934MHz setup,complete with power/SWR meter, beam and a mint condition Cybernet Delta 1, still in working order but useless and yes, we did need to buy a licence but the fee was dropped after a few years, just requiring registration.

[james_s]

In the US there is a 900MHz ISM band today, it's used by some cordless (landline) phones, and various wireless devices, my weather station uses 900MHz to transmit from the sensor suite to the console. 

[Lord of nothing]

How about the 800Mhz Band?