CB Radio Use

[hansomcommon]

Excellent series of reminiscences.

I still use the CB but have given up the 1kW burner I built (4 EL519's) as it is not needed now.

[Junk Box Nick]

Just musing but everyone had to have a 'handle' on CB, in the same way that we have forum names. When CB became legal were/are there instances of licensed amateurs using their call-signs as handles on the CB bands?

[russell_w_b]

Originally Posted by Junk Box Nick

'When CB became legal were/are there instances of licensed amateurs using their call-signs as handles on the CB bands?'

I didn't think you were allowed to do that as it would fall foul of your amateur licence conditions by working 'out of band'. I'm not saying it didn't happen, mind...

In any case, I would think that any amateur rash enough to issue their callsign on the CB channels would get a flea in their ear off the non-amateur fraternity!

Any amateurs I knew who used both CB and amateur radio put a different hat on when they picked up the appropriate mic.

[Biggles]

Funnily enough, my "handle" was the same as my present forum name, which historically came about by wearing a WWII flying jacket while riding my motorbike at the time. Still got the jacket, and a few motorbikes too. Nothing changes.

[SiriusHardware]

Originally Posted by 'LIVEWIRE?'

Whilst on this subject, did any forum member ever use the 'K40' microphone?

I still have one in my collection, although it's a late version which doesn't have the grey signal screening compound painted on the inside of the enclosure.

I don't use it because the extremely high preset level of compression sounds very harsh on FM - they were designed for, and sound much better on, AM and SSB. In fact, they made AM sound as hard and clean as FM normally does. On SSB they made a phenomenal difference to the average power being transmitted.

I did toy with the idea of wiring it to my FT290 R2 to increase the effectiveness of its meagre 2.5W on SSB.

Originally Posted by 'LIVEWIRE?'

Anyone remember a device called 'Selcall' (Selective Calling), which was a small 'add-on' box containing a circuit which allowed only other user(s) eqipped with a Selcall unit set to the same code to listen to, and talk to you.

Widely used in PMR systems, there were some very good dedicated tone encoder / tone decoder chips such as the FX503 / FX003 series which I didn't have access to until later, at which point the majority of the people I might have used selcall with had drifted away from CB. I could have done so much more if the cheap flash microcontrollers we have around now had been available then. One CB brand - 'Ham International' - did actually put specific connectors for their own optional selcall units on the rear panels of their radios, but I never ever saw one of their selcall units and they didn't supply radios for the UK legal market (or any other legal market, as far as I know!).

Incidentally none of these selective calling systems, whether single tone or CTCSS (still widely used) prevent anyone else from listening to your transmissions - it's just a way of allowing your radio to stay muted until the person you are looking out for calls you. What you described, strictly speaking, sounds more like voice scrambling / encryption which is different from selective calling.

Originally Posted by 'LIVEWIRE?'

Re; Cybernet. Radiomobile CB Transceivers were rebadged Cybernet models. They sold both the basic and the Higher Spec. versions.

I think the Radiomobile badged radios were initially produced with the idea of their being pre-installed in some new cars and I believe that did happen in a limited way.

The Radiomobile radios were rebadged versions of the 'Cybernet' branded 1000, 2000, and 3000, the latter using the ubiquitous 134 chassis yet again, and the two smaller radios using what was basically a miniaturised version of the 134 chassis, namely the 135 chassis.

The Cybernet / Radiomobile badged radios were untypical for Cybernet-built radios in that they used LED bargraph meters, which I never liked because they were so low-resolution (typically only four LEDs).

Despite that, my collection also includes a Cybernet 1000.

[electronicskip]

I still use CB Radio to this day, I have one in my car and I have a base station too.
Finally we do have SSB , at the moment there is only one completley legal rig that runs SSB correctly.

Originally Posted by 'LIVEWIRE?'

did any forum member ever use the 'K40' microphone?

I have a K40 Magmount Twig on my car right now

[Techman]

The squelch mod described by sirius sounds good and I can see how that would work quite nicely, but the Barracuda will remain as it is, although it might be worth a go on one of the other radios with the annoying audio output stage squelch 'bop'.

I bought a number of items brand new back in the early days, ie 1980-81(ish), but most of the stuff I've got has been given as broken junk from clearouts, or bought as a cheap job lot or maybe as a swap for something.

I've got one of those Bermec power supplies shown in the original 'for sale' thread and other than the terminals coming loose it's still working fine. I do know that there could be the potential for around 30 volts if that power transistor goes short as I've also got a Bremi version of the same thing that packed up (no output) the other day after not being used for several weeks, but it was a couple of other components that had failed. While fault finding on it, I noted that there was around 30 volts just after the rectifier.

I've got one of those old K40 mics with the magnetic back. These take their power from the radio to charge an electrolytic capacitor which gives a 'certain length' of talk time per 'key'. I don't remember how I came to have this mic and I've never used it, but I'll give it a try sometime.

In my opinion, the best microphone for general bench use is the Ham-master 4200. There were a couple of other versions of this same mic made under different badges. These work very well as long as you don't mind giving the switch and mechanics a bit of attention every so often. I bought one of these brand new and then got another one with a load of old gear. Interestingly, they are both identical, but they sound slightly different when tested side by side.

I have one of the baby Cybernets (Cybernet 1000) all original and in its box. I used to have this fitted in a MK1 Escort van, but it packed up years ago and got put back in its box, so that's another little job for a dull day!

Grandstand - There were a number of 'rigs' made with this brand name. A couple were small and sounded dreadful on transmit, like an Amstrad 901 (some people will know what I mean by that). The other two used a factory converted AM board and these were the 'Gemini' and its big brother, the 'Homebase'. Either of these with a Ham-master 4200 (or equiv 232) base mic with a bit of 'room resonance' picked up with the 'speech processor' in the mic is about the best sound you'll EVER hear on legal FM CB. I remember folk describing the transmitted sound from these radios as 'BBC quality' - of course it isn't BBC quality, but you get the point. I've got a Gemini that I picked up as a 'dud' about 20 years ago. I spent some time on it a few months ago and it worked well for a while, but has now gone intermittent, so that's another job. I seem to remember hearing that these radios often couldn't be repaired due to some specialised parts (chips?) that are no longer available. The receive on these isn't that great and the squelch is either on or off, but the transmit sound with a base station microphone of the 4200 type is second to none. It has to be said though, that these sets do sound quite dull when used with their standard hand mic, so not so good when used mobile. The Homebase version looks very professional with all the extras and a clock, but it uses the same main board as the mobile Gemini version.

Fidelity - I'm sure I've got the butchered remains of a Fidelity 1000 somewhere and as someone mentioned, I've got a lot of photocopied circuits for various radios - and like someone said, I need them in A3 size now too!

Aerials - I've found that several of my surviving aerials have needed attention due to corrosion within the connections to the loading coils etc.

Remember the DV27? My first ever 'proper' aerial. I had one of these fitted to the Escort van. Due to its light colour, I wound it from bottom to top with black insulating tape so that it didn't stand out while driving round town. These are a great aerial and I've still got mine, although it's been broken and mended several times, so wouldn't be any good to run mobile, but would be good as a loft aerial.

Someone mentioned a 1KW burner. I remember the Bremi BRL500 with 4 x EL509/519 and a 5th one as a driver. These were made down to a price and could be very un-reliable. Someone brought one round to my house where I used to live and left it with me to play with for a few days - at least these had a fan to keep things cool!

There were the single valve versions (Zetagi BV131) that used either a 6KD6 (or an EL509 in the slightly later ones). Over half an amp and 1000 volts HT via a voltage doubler from a transformer wound for 220 volt mains running on 240 or more, what with the heat radiated from the valve, these soon cooked themselves! I got asked to repair one of these a few months ago - a rare survivor. The chap was very pleased as he couldn't find anyone else who would touch this old valve technology - especially one of those!

As a last point. I think that time has proven that the 'powers that be' have got better things to do than spend countless man-hours chasing illegal equipement, unless it's causing a problem. So the law is in place to use as a 'tool' to take someone off the air and confiscate equipement should there be a serious problem that couldn't be sorted out with a warning first. Infact, I can't say as I've heard of any problems at all lately, but then I only plug the aerial in and have a 'flick round' and listen, or a quick word once every couple of weeks.

[G6Tanuki]

Originally Posted by Techman

Remember the DV27? My first ever 'proper' aerial. I had one of these fitted to the Escort van. Due to its light colour, I wound it from bottom to top with black insulating tape so that it didn't stand out while driving round town. These are a great aerial and I've still got mine, although it's been broken and mended several times, so wouldn't be any good to run mobile, but would be good as a loft aerial.

There was also its big-brother the DX27 - longer, a thicker.stronger GRP former, thicker wire for the winding, and worked a lot better!

Back in the late-70s/early-80s CB using the old 23-channel AM rigs was really quite commonplace in rural areas, being used by farmers/foresters/gamekeepers/estate-manager types - who were generally not well-disposed to "CB-nerds" who took up residence on hiltops and used the channels for inane chat rather than more-serious applications!

These days even though mobile phones are ubiquitous good signal-coverage isn't - so you'll often still see tractors/Land-Rovers/combine-harvesters etc. fitted with CB.

[Restoration73]

One of the more interesting base aerial installations I saw had many joins in the coax (i.e.
2 x PL-259 plugs and double end socket). I asked the operator why this was. He said "that
to reduce the SWR the coax had to be cut into an odd number of quarter wavelengths"
I did not ask him if he knew what the cable velocity factor was.

[G4XWDJim]

My kids in their teens in the early 80s wanted a CB and eventually to gain an easier life I relented and bought them a legal one from a rally, being very careful to check that no-one I knew was watching as I smuggled it out under my coat.

I put them a concealed wire aerial in the loft which gave them excellent coverage and denied all knowledge of it to amateur friends. Fortunately the craze didn't last long and neither of them wanted to become amateurs.

On the subject of illegal AM/SSB CB units I was told by someone with a technical position in whoever were the radio authorities at the time that those AM/SSB units were considered to be illicit, which apparently is on a level with drugs and much more serious than merely illegal, whatever that might mean.

Jim

[G6Tanuki]

Originally Posted by G4XWDJim

On the subject of illegal AM/SSB CB units I was told by someone with a technical position in whoever were the radio authorities at the time that those AM/SSB units were considered to be illicit, which apparently is on a level with drugs and much more serious than merely illegal, whatever that might mean

The 'illicit'-ness being that since they were invariably smuggled, the smuggler could not prove that the relevant import-duties and sales-taxes had been paid.

Thus, CBs could be seized by HM Customs & Excise as 'contraband' irrespective of whether they were actually installed/used to transmit radio signals. This tactic was used against the various ~dealers~ who advertised in places like Exchange&Mart rather than against individual users.

[Techman]

I think I was given a DX27 with some other scrap parts years ago. It had been broken at the top. I did a bodge repair on it and it's around somewhere with the other aerial bits. These were good but because of their 'bulk' they really needed a metal plate added under the body panel of any vehicle they were fixed to - there was a lot of stress to the DV mount with these 'twigs'!

When I first put up my little aerial on the top of the TV aerial last year, I was determined not to spend ANY money on CB radio and just use the bits that I'd already got. I found the various lengths of 30 plus year old RG58 50 ohm coax that had survived and joined them all together and it seemed to work quite well - I did use PL259 plugs and sockets that were laying around to do the job, though. I then decided to treat myself to a length of brand new coax to replace the length with all the joins in, and there was no difference in signal in or out that I could detect, although you'd think there would be some.

The original idea was to have the radio in the living room in a cupboard that I already have a Hi-Fi and computer built into that is also connected to the TV. As I already have wiring from outside and other places running into this cupboard I thought it would keep everything together and out of sight. I had a very long expandable mic lead made out of several mic leads joined together and the idea was that in a late evening I could laze on the settee with the Ham-Master 4200 on a low table and chat.

This didn't work out, mainly due to me keep wanting to use or try out different radios. So I ended up using the old coax with all the joins as an extension lead within the house to take the aerial line through to my workshop room where I fitted a shelf to hold them all. The daft thing is that the receive and transmit seems to work just as well as it did before. The extra length brings the 'apparent' SWR down to a very low reading all round. This is just a bodge up for the time being and the long term idea will be to run a proper continuous length of coax from the aerial directly to the work/play/radio room.

The first 'proper' homebase aerial I bought was a GPE27 5/8th wave, back around 1981. It moved house with me in around 1984, but I stupidly left it on the house when I moved again in 1999. I had been given another one of these which I've kept. It was in very good condition and I'd kept it in the box that my original one was bought in. I think it was when I first moved to where I am now, but could have been a couple of years later, I stuck this aerial on a bit of a pole just to try things out. It then got slung behind the garden shed, still fully extended to 22' - untill I dragged it out a while back. It had suffered and was a bit 'green' and was also full of water. It's spent a while telescoped down and standing in a warm place so as to dry/drain all of the years of water out. It seems to be ok and tests out fine on 'ohms'. I'm tempted to put this aerial up but it's a bit big and will stand out (and they also make a noise in the wind) - unlike what I have now, that can hardly be seen - I even had to point it out to the neighbour who hadn't noticed it!

[SiriusHardware]

A large CB half-wave or 5/8 wave will usually have a dead short (as far as any ohm meter is concerned) between the inner and outer parts of the SO239 socket on the base. This is because there is an internally mounted matching coil wired between the two points.

Amateurs quite often remove these internal coils so they can use the aerials as free standing vertical 'long wires' in conjunction with an aerial tuner unit. But for CB use, it should be there so if your example does not have a short from inner to outer, worry about that. The coil may have rotted away while the unit has been full of water.

When I was first involved in CB the first commercially made base station aerial I bought was a an aluminium quarter-wave ground plane which had a 9ft vertical element and three horizontal 9ft ground plane radials.

When I bought it I think I really had not thought through how big a quarter wave was at 27Mhz. But the oddest thing about it (so I thought at the time) was a strange looking carefully shaped, cranked bit of wire like a piece of coathanger wire which, if fitted, shorted the base of the vertical radiator to the plate upon which the radials were mounted. I took one look at it and thought 'I'm not fitting that! That's going to short out my transmitter output and kill my reception dead!".

It wasn't until some years later that I realised what it had been: A Gamma match. By that time I had moved on to the ubiquitous half-wave vertical. Anyone who is serious about CB shouldn't mess around with anything less than a 1/2 wave or 5/8th wave vertical, as they are so superior to any other practical aerial for the band.

It's true that they are noisy in the wind and your neighbours will be less accepting of one than they might have been in the 1980s, but if you can put one up, that's the way to go.

[SiriusHardware]

Originally Posted by G6Tanuki

Thus, CBs could be seized by HM Customs & Excise as 'contraband' irrespective of whether they were actually installed/used to transmit radio signals. This tactic was used against the various ~dealers~ who advertised in places like Exchange&Mart rather than against individual users.

There were a couple of interesting exceptions to this - one involving the Isle of Man - for some reason (a loophole?) they could be imported into the Isle of Man legally, import duty paid on them, and then once they were there, they could be brought legally into the rest of the UK.

Another dodge involved removing a critical part (typically the synthesiser reference crystal) before importing them, because then they weren't functional on any frequency and couldn't be described as '27Mhz band transceivers'. Said parts arrived separately and then were reunited with the units later.

Even in either of these cases the radios were, of course, still illegal to use.

['LIVEWIRE?']

I always understood that owning an american spec. CB was legal, though installation and use was illegal. Those imported from the Ilse of Man, which, sorry to be pedantic is not part of the UK, would certainly fall into that category, as, presumably, would those from which the synthesiser crystal had been removed.

[G0HZU_JMR]

I'm not sure anyone really cares about the legality of ownership of the old export CBs these days. I certainly had a lot of fun on CB in the early 1980s

I've got a pile of 148GTL-DXs 'somewhere in the loft' (some still boxed and unmarked) and an old SS360FM and a Major 588 here . I've got an old school CB 27/81 FM radio somewhere here as well.

One day I might try the 148s out on AM/SSB on the mid channels but I doubt there will be anyone on there to talk to!

[Techman]

Hi SirusHardware, yes, I should have made that a bit clearer when I said about checking the 'ohms' of the aerial. It did measure as a 'short', so the loading coil 'should' be ok. I think these have a 'tapped' loading coil with the tap close to the bottom end and going to the centre of the SO239 socket and with the bottom end of the coil going to outside (screen). This is how I think they must be constructed, but I've never cut one open to see exactly. It's certainly been corrosion that has caused either variation in resistance readings or open circuits on a couple of other aerials that I was playing with a while back, but these aerials were designed to not have the tapped coil and should read as 'open circuit' across the input. With my bottom loaded steel whip that I've fitted on the TV aerial, this was giving variable readings 'through' the loading coil when it was flexed. I had to cut away some of the shrunk on insulation and clean up both ends of the coil and its connection point with a small file, then solder with a high wattage iron, then re-insulate. The DV27 was open circuit or high resistance in about four places. There's a lot more to the innards of a DV27 than I thought. They were very good value for under a fiver at the time!

There's actually a bit of a story to the 'mobile' whip that I've fitted up. It wasn't actually sold as a mobile version of the aerial, but as a 'homebase' aerial. It was originally a 'better' version of the famous 'centre fed 9x9 dipole'.
I was again given this by a pal who was having a clear out probably 25 years ago. The lower 9ft ground plane was missing and all that was left was the bottom loaded whip which was bolted to part of the original centre mount. I took it apart and used the aerial as a mobile. Although it had a bolt hole drilled through the bottom metal part, it still had the threaded part at the very bottom to screw into an adaptor for a DV mount and I had this aerial fitted on the rear wing of my MK1 Jaguar XJ6 for many years. The DV mount remained for a long time even if the aerial wasn't always fitted. There was already a hole for such an aerial on the car when I bought it, so this was ideal. When I decided to use this aerial as a homebase aerial once again, I hunted high and low for the remains of the original mount. I was sure I'd seen it sometime in the years since I'd moved, and sure enough I hadn't thrown it out and it eventually came to light. It was 'complete' enough (just) to use it to fit the aerial to a length of tube coming out from just under the actual TV aerial itself. So with the bits of joined together FM aerial as a ground plane, it's very much as it would have been when it was originally sold.

I have a question - I just can't remember what these aerials were called when sold as a homebase aerial. I did have a search on-line, but couldn't find anything. The name 'wot-pole' (spelling?) springs to mind. I still see the person that I got it from and he seems to think the same. Confirmation would be good, also, what was the name of the 'whip' when it was sold as a mobile aerial?

As to the last post - I totally agree that no one really cares these days about the legality of any of these old radios and aerials from over 30 years ago - it's common sense really.

[Biggles]

A while ago a friend of mine found some 934MHz CB gear in a loft. He was wondering what it was and how much it might be worth. I suggested eBay or car boot sales to sell them but I'm not sure if he ever managed to get rid of any. It was the first time I had actually seen 934MHz sets as they weren't too common even when they were legal.

[teetoon]

Hi Techman, you're right with the "Wot Pole" and the whip on it's own was called a "Half Breed". The wot poles seemed to work quite well with that 9ft lower radial. I had one hanging in the gutter for a while back in the day. I had a GP 27 as well strapped to my dormer window frame and when the wind got up I would have to take it down as I couldn't sleep with the noise!

I spent quite a lot on rigs in the 80's starting off with a straight 40 General Electric, then a Major 360, High Gain 5, Colt 1200 DX, Ham International Jumbo (my favourite) and a couple of Cobra 148 GTL DX but when it all went legal it was a waste of time (to me). Still got a Colt Excalibur that could do with a clean up but when I've listened there's not much going on in the UK. A couple years back there was regular activity on channel 6 from the states during the winter months but I haven't turned it on since moving house 16 months ago.

David.

[SiriusHardware]

Originally Posted by 'LIVEWIRE?'

I always understood that owning an american spec. CB was legal, though installation and use was illegal.

The default was that they were illegal even to have in your possession because they had probably bypassed the whole import duty system, except for:-

Originally Posted by 'LIVEWIRE?'

Those imported from the Isle of Man, which, sorry to be pedantic is not part of the UK, would certainly fall into that category, as, presumably, would those from which the synthesiser crystal had been removed.

-just as you surmised. And sorry for 'misplacing' the Isle of Man.

I can specifically remember a very neat little model with the unpromising name of the 'Jaws Mk2' being offered under the 'missing crystal' scheme by one seller at a very high price (around £200), due to its legally imported status. I reckon that in 1979, £200 would have bought a reasonable second hand car.

Although I never saw a Jaws Mk2 I have a rather rare CB/27/81 Colt 355 which appears to have used the same casing / front panel tooling. It's even smaller than the Cybernet 1000 mentioned in a couple of posts earlier.

Techman, I agree that aerial was called a Wot-pole. The recipe for that went like this:

Take a straight dipole, which has a natural impedance of about 72-75 ohms, and bend the elements together so there is an inside angle of about 120 degrees between them. This gives it an impedance of about 50 ohms, so correct for direct connection to a CB radio without any form of ATU. In other words, it's a single band inverted 'V' dipole.

Then re-orient this bent dipole so that the element connected to the coax inner is sticking straight up in the air.

Then, replace that element with a loaded, shortened electrically equivalent mobile aerial to reduce the overall height of the aerial. Job done.

The mobile aerial used was the basic base-loaded aerial of the time, essentially a copy of the Valor 'Half-Breed'. (Valor, an American company, had a phase where they gave some of their CB aerials native-American related names. The centre loaded CB mobile sold by them at the same time was called the 'Warrior'). I do believe Valor also made the original Firestiks as well.