Look what I dug out of the internet

[3metrejim]

Seeing as I got a little fed up of "I'll have a look in the junk pile", etc.. I did some online digging.

I managed to find a picture of Albert's famous UHF link, using the pye pocketfone. See picture below.

I also found out who was the best transmitter builder in London, you can check for yourself on this page:

https://www.horizonradiolondon.com/hori ... room-team/

Link picture lifted from:

https://www.horizonradiolondon.com/hori ... nsmitters/

If you want to pull anything from those pages, then disable javascript (you'll have to use a PC or laptop) as someone has gone to a whole lot of trouble to stop copy/paste, save, print, etc... (no idea why in this day and age). To print, open dev tools on your browser (when visiting with javascript off) and look for a style attribute with @media print and delete the style element.

[Albert H]

Pyers was very good at copying Kenny Myers' gear! The first PF1 link was hacked together by Myers with an IF that came from a company called "Hart" - they sold IF boards with stereo decoders on them - two-chip things which used to cost about £4. The stereo decoder pilot tone oscillator could be moved (usually up to around 23kHz) for tone access, using the pilot detect LED output to switch the logic. The PF1 TX & RX pairs came from "Garex" for around £6 a pair, and they were usually in dreadful condition, with cracked cases and they'd often been wet! Some of them came with the original rechargeable batteries, but these were invariably useless and frequently leaking!

My PF1 and PF2-based links were a bit different - I used to saw off the original RX IF, squelch and audio amp, and used an external overtone crystal oscillator at around 90 MHz to drive the Local Oscillator multiplier chain. This was a more convenient approach, because it was easier to change crystals to choose a link frequency.

Similarly, the TX had the phase modulator and crystal oscillator sawn off, and a rockbound PLL-controlled oscillator drove the multiplier chain. With careful tweaking, it was possible to get as much as 200mW out of the transmitter, but they were more usually aound 120 - 150 mW, and running cold. The output match was modified to feed into 75Ω (instead of the eye-poking pop-up whip!) to allow the use of cheap TV aerials.

Later on, we abandoned the use of the PF1s (the supply began to dry up), and one of our number (Marcus) came up with a neat double-sided PCB that had both the TX and RX on one sheet - we used to guillotine them for the individual boards. The circuit was one I came up with after experimenting on 70cm and I built a few early ones point-to-point over copperclad. A few were used as link repeaters - in on Band V and out on Band IV - with both sections as one board (with a PCB-material screen between them).

The transmitter strip was really simple, with a Colpitts oscillator feeding a buffer stage. The collector of the buffer went to the doubler stage, and the emitter fed a prescaler IC (÷128) for the PLL. There was then a pre-drive stage feeding into a push-push amplifier stage (two grounded-base 2N3866s) that would give a bit over a Watt. We did make a few higher power ones (using PT8811 as I recall) that were used in the dodgier parts of Central Europe.

All the Band IV and Band V stuff was built at 75Ω to make use of TV aerials. It saved a huge amount of time and money, though one of us did make a few PCB-etched log-periodic aerials as an experiment. They worked, but is was cheaper and quicker to go to Homebase or B&Q for the aerials, poles and mounting brackets. In those days we could get the Antiference "kits" for about £11 a go, which was an aerial (usually 18-element or more), coax, Belling-Lee plug, mounting clamp, a short pole and pole clamp - and even the screws and Rawlplugs to attach it to a building!

When I'm back in the UK, I'll see if I can find a few photos of that stuff.

Incidentally, Pyers was pretty good at getting plenty of power out of recaltricant transistors, but his "designs" were generally copies. The exciter circuit on that webpage you pointed out above was actually the old RFL circuit from the 70s!

[sinus trouble]

Excellent find 3mtrjim!

I really enjoyed reading through this link!

However, I do not understand this attack on engineers?? Pyers may have been a magnificent engineer? I dont know? I was just a kid at that time!

Thats no reason to discount the phenomenal talent of other engineers that i wont name!

I have the upmost respect for anyone who contributes to radio! Both experts and those who are willing to take the risk and learn from mistakes!

[3metrejim]

I do not understand this attack on engineers??

Far from any attack, Sinus. Consider this:

FM radio is quickly becoming archaic technology, pirate radio (in the UK especially) is becoming pointless. So sharing of old designs, and I don't mean circuit diagrams to copy; just photographs, so that the stories are preserved along with examples of the matching old equipment as done by the above website, and others.

Yourself: Many designs, shared (far beyond what most would expect, for nothing).

Zozo: Another design (variant of old BCW, new board and PLL), over and above what you'd expect for nothing.

Reverend: Many designs, even with full diagrams (Showing there is virtually nothing to be made from these things nowadays but a good way to get rid of stock of old components to enthusiasts / tech historians). I'm also amused how Reverend started in the shed (ZFM): very similar to my own experiences (must say my parents weren't best pleased, but it kept me in my room and somewhat quiet at least).

Myself: A bit of ancient PIC re-coding (gave me something to do, that maybe would come in handy for someone). PS, If anyone has an old anti-theft exciter (cannot re-tune because it's fixed in a PIC), I can probably sort that for you (no promises though, but if I decide to, then you'll get full source and instructions for frequency change with it).

Notice how all of the stuff above is also new to some degree, not something that you can find online (my excuse is that the code is updated, and the only place it's been posted, by myself anyway, is on this site).

A good engineer will usually pass on things that are somewhat useful (time constraints permitting, I guess), without handing over their products to blindly copy. A good example was with the NRG workshop, my favourite there was the 'amplifier stability' article - extremely handy if you are just starting out with low power power amplifiers (I learnt by mistakes, most definitely, there).

Pyers was pretty good at getting plenty of power out of recaltricant transistors, but his "designs" were generally copies. The exciter circuit on that webpage you pointed out above was actually the old RFL circuit from the 70s!

( viewtopic.php?t=3439#p40063 )

If there are any mistakes in the horizon website, it may be a good idea to contact them, and get them to make sure the story is accurate.

One thing I always remember: "A man is only as good as his word", I've now run out of fingers to count the next quote, or variants of, on:

When I'm back in the UK, I'll see if I can find a few photos of that stuff.

^^No need to come back, just get whoever is looking after it to take a few shots (pictures): We have had the Internet for some time now. I guess maybe a Dutch influence (Marcus), who'd want to come back to this pathetic place anyway?

Anyway: For anyone interested to see what's inside the old PF1, (it's remarkable how tiny it was considering there was no SMT when it was made). It is very simple by modern standards, but you'll never change how RF works.

[3metrejim]

Pyers may have been a magnificent engineer? I dont know? I was just a kid at that time!

I don't know either from personal experience, but there are plenty of signs that he was pretty damn good. The Horizon website, appearance in a documentary 'making waves' (and another much later, but cant remember what it was called). Director of two businesses making radio gear and a business of his own now.

You'll like this old manual to learn from, the descriptions are easy to understand, and you can follow along on the diagrams. The link is from the amateur YO4HFU website https://www.qsl.net/yo4hfu/Projects.html (instead of telling you which link to go for). strange how they use a (modified) broadcast warehouse exciter though.

Link for manual: (actually embeds so readable here...)

[Albert H]

Two things to note from that manual - the exciter isn't actually a modified BW exciter - the BW exciter was a modification of someone else's work! Mr Webb (aka "T1") would probably be annoyed to see his work attributed to somebody else. His was the first "at frequency" circuit I saw that was reasonably stable. That said, when Roger (and Pyers) used that design in "one-box" configurations, they frequently had hum issues that took longer to iron out than the rest of the design took.

Also, the Limiter is based on a design published (with errors as usual) in Electronics Today International. The feedback 13600 circuit is based on a TCA attenuator I designed with the very first Transconductance Amps (Philips NE5517) in the late '70s (at Philips). The performance of the TCAs was quite poor (compared to the op-amps available at the time), so the idea of including one to vary the negative feedback around an op-amp meant that we could make use of the distortion cancelling properties of the negative feedback loop, whilst the limited TCA bandwidth (compared to the op-amp) wouldn't be too much of a problem.

The original sidechain used a mono source - the audio from both channels was combined before the rectifier, and I could never see why ETI (and Pyers) used separate rectifiers for each channel, only to combined their rectified voltages with a couple of diodes.... Combining the sidechain feeds minimised the risk of channel-to-channel offsets (messing up the stereo image) and reducing the number of calibration points needed. I suppose that with two rectifiers it would be simpler to build a twin-mono version for other studio use, but it's still a strange choice.

The ETI limiter had a couple of properties that made it quite good for broadcast purposes - the attack time was remarkably short (around 450µs), and it was easy to adjust the decay time. It also tended not to overshoot (too badly), and it could be configured for de-essing as well. The biggest problem was the limited range of attenuation - typically about 24dB in that configuration - and the finite attack time meant that a clipper was essential after the limiter (adding distortion to peaks) if you really wanted to prevent overdeviation.

Roger's version of that limiter had a switch selectable input sensitivity, and a green bi-directional LED effectively across the output to provide symmetrical clipping (at almost exactly PPM 6 with the diode he used). He also added a balanced input (using an expensive SSM chip), but retained an unbalanced output, making the board only really suitable for the use he put it to - a balanced output option would have allowed the Limiter to be used more widely.

Incidentally, there was an earlier version of the FM30, with a very different exciter (a multiplier one) and using the BGY33 (or 133) Philips RF Power module for the output stage. The unavailability of those RF block modules made the design of a discrete Power Amp necessary!

[Shedbuilt]

This (from the Horizon transmitters link), is quite a nasty design. I received a blown Tx with this exciter design, in about 1985. The exciter was built with the stick on squares method, with an ugly built PA too. The PA had blown it's output transistor, and the station were going to bin it. The exciter and PA were in separate boxes, and the coax used to power the exciter board (choke at each end, to separate the DC and RF). The two boxes were mounted on blockboard, with the power supply built separately on the blockboard. Apart from the transformer, rectifier, cap and 15v regulator, there were four, fairly large heatsinks, each individually screwed to the blockboard, each with a single TIP3055 (parallel emitter followers, with load sharing emitter resistors), to give about 14.3v regulated supply. I replaced the output transistor with a BLY90, and it came to life. I'd been experimenting with transmitters, and at that time, the exciter design was better than anything I'd come up with, so I drew the schematic out from the PCB, and built a couple, stick on square method. After that, I made a PCB for it (old school, tape on film), bought a UV box, and built a few. The exciter has a few weak points. The worst, in my opinion, is a tendency to sprog. The main culprit there, is the oscillator. If replaced by a more conventional Colpitts oscillator, the spurious emissions reduce dramatically. Improvements in the doubler and harmonic selection area, will help with other (frequency related) emissions. The output match is obviously not suitable for driving an aerial directly, but would usually be used as an exciter (to drive a PA). The RF part of this, is extremely similar to one of the widely seen exciter boards of the 80s and 90s (albeit with the addition of an Op Amp equipped active pre-emphasis circuit, second varicap to facilitate fixed frequency CMOS PLL).

[Albert H]

Remember - that was "designed" by the wonderful Pyers.....

Nuff said.

Those "ugly" built rigs were thrown together as cheaply as possible, to avaoid expensive losses to the Post Office / DTI / whoever....

The cheapest of the cheap were the little 65 Watt rigs that came from Ealing. These actually had etched PCBs, and used an oscillator that ran at frequency, at about 1 Watt! They even did away with trimmers - they used fixed value caps, and bent the coils to tune the things!

[3metrejim]

Sure the horizon site mentioned that the drifty rig, like that shown above, was before Pyers. But I only have their word to go on. They were the awful 'toy rigs' I used for experimental purposes, when I had no idea how to build something that didn't drift around and stages other than the oscillator started oscillating when trying to tune (power jumping around, with pops, squeals and odd noises coming out of a nearby receiver), but that is all the first pirate I met was willing to part with. I had to save up and buy some books (no internet like now at that time): RF circuit design (Chris Bowick) - nice tables for filter design, Newnes practical RF handbook - general design information and plls, and the RSGB vhf/uhf manual - the pirate bible at the time. A fair bit of reading to do before I could make anything better.

On a slight different note, and I'm sure this will interest Albert, is what you can find out from metadata stored in files (the pdf from sbs). Turns out the author of the document is the same person that drew the schematics for some pages. Whether he designed it as well, I don't know. What is known, is that he's a consultant engineer for radio installations now, and for the past 20 years, and travels the world. I guess working in a radio engineering environment paid off for that guy.

[3metrejim]

The original sidechain used a mono source - the audio from both channels was combined before the rectifier, and I could never see why ETI (and Pyers) used separate rectifiers for each channel, only to combined their rectified voltages with a couple of diodes.... Combining the sidechain feeds minimised the risk of channel-to-channel offsets (messing up the stereo image) and reducing the number of calibration points needed. I suppose that with two rectifiers it would be simpler to build a twin-mono version for other studio use, but it's still a strange choice.

I wondered the same thing with simple limiters / compressors , but came up with that if you put in a signal to each channel with one being exactly, or close to, 180 degrees out of phase with the other and equal levels, the side chain would add them to mono and see zero, and do nothing. Probably doesn't happen much with most music, but maybe with pathological inputs - Probably with electronic dance music, that has synthesised sounds, it might happen more often. Murphys law: If it can happen then it will (at some point - Aphex Twin?).

[Shedbuilt]

Sure the horizon site mentioned that the drifty rig, like that shown above, was before Pyers. But I only have their word to go on. They were the awful 'toy rigs' I used for experimental purposes, when I had no idea how to build something that didn't drift around and stages other than the oscillator started oscillating when trying to tune (power jumping around, with pops, squeals and odd noises coming out of a nearby receiver), but that is all the first pirate I met was willing to part with. I had to save up and buy some books (no internet like now at that time): RF circuit design (Chris Bowick) - nice tables for filter design, Newnes practical RF handbook - general design information and plls, and the RSGB vhf/uhf manual - the pirate bible at the time. A fair bit of reading to do before I could make anything better.

Very, very similar to my own history. My Dad had one of the RSGB books (handbook I think). I bought the small hardback book, which was primarily data, and had all the data for calculating several types of matching network. I bought the Bowick book, a PLL design book, and a Motorola power amp book, from The Modern Book Shop (or Company, can’t remember which), in Praed St, at great expense. I found the VHF/UHF manual a bit later.

[shorty]

This (from the Horizon transmitters link), is quite a nasty design. I received a blown Tx with this exciter design, in about 1985. The exciter was built with the stick on squares method, with an ugly built PA too. The PA had blown it's output transistor, and the station were going to bin it. The exciter and PA were in separate boxes, and the coax used to power the exciter board (choke at each end, to separate the DC and RF). The two boxes were mounted on blockboard, with the power supply built separately on the blockboard. Apart from the transformer, rectifier, cap and 15v regulator, there were four, fairly large heatsinks, each individually screwed to the blockboard, each with a single TIP3055 (parallel emitter followers, with load sharing emitter resistors), to give about 14.3v regulated supply. I replaced the output transistor with a BLY90, and it came to life. I'd been experimenting with transmitters, and at that time, the exciter design was better than anything I'd come up with, so I drew the schematic out from the PCB, and built a couple, stick on square method. After that, I made a PCB for it (old school, tape on film), bought a UV box, and built a few. The exciter has a few weak points. The worst, in my opinion, is a tendency to sprog. The main culprit there, is the oscillator. If replaced by a more conventional Colpitts oscillator, the spurious emissions reduce dramatically. Improvements in the doubler and harmonic selection area, will help with other (frequency related) emissions. The output match is obviously not suitable for driving an aerial directly, but would usually be used as an exciter (to drive a PA). The RF part of this, is extremely similar to one of the widely seen exciter boards of the 80s and 90s (albeit with the addition of an Op Amp equipped active pre-emphasis circuit, second varicap to facilitate fixed frequency CMOS PLL).

I got a similar 1 watt exciter with the improvements you describe around 90/91 from S I, it came on a double sided tinned pcb, BSX20's in the oscillator, buffer, doubler, a 2n4427 output, a yellow toko coil in the doubler stage, the buffer i seem to recall had a hand wound 8 turn coil.
I don't think S I designed or built the one i recieved as when i got a second exciter from him it was a rats nest of components on a scrap of copper clad board that didn't work, i think he'd tried to copy the one he sent me, it could have been designed/made by roger as they later went onto work together, not 100% sure who designed/built it as i've never seen another, i copied the circuit and pcb layout and made a couple.

[3metrejim]

Incidentally, there was an earlier version of the FM30, with a very different exciter (a multiplier one) and using the BGY33 (or 133) Philips RF Power module for the output stage. The unavailability of those RF block modules made the design of a discrete Power Amp necessary!

Unfortunately, I couldn't obtain the technical manual for that version. If there is one, it likely predates the widespread use of the PDF file format. I just have the one where an at-frequency oscillator with a CMOS PLL, set with BCD switches, is used (PLL 3).

I do have some diagrams for circuitry that uses a multiplier with a BGY33 module. It was widely available online once upon a time, and was attributed to 'BiasComms' accodring to the diagram (their diagrams are quite easy to recognise from the bitmap and low resolution nature of the component symbols). There was also a stereo coder (very similar to the first budget one from NRG - the one not knowing left from right) and Medium wave circuitry. The phrase they used was "Everything gets easier with practice, except getting up in the morning!", they were once active on alt.pirate.radio (remember those groups?).

A link. You can already see slating of "veronica" gear at this early time: https://groups.google.com/g/alt.pirate. ... lVro?pli=1

[trancetechnic]

Incidentally, there was an earlier version of the FM30, with a very different exciter (a multiplier one) and using the BGY33 (or 133) Philips RF Power module for the output stage. The unavailability of those RF block modules made the design of a discrete Power Amp necessary!

Unfortunately, I couldn't obtain the technical manual for that version. If there is one, it likely predates the widespread use of the PDF file format. I just have the one where an at-frequency oscillator with a CMOS PLL, set with BCD switches, is used (PLL 3).

I do have some diagrams for circuitry that uses a multiplier with a BGY33 module. It was widely available online once upon a time, and was attributed to 'BiasComms' accodring to the diagram (their diagrams are quite easy to recognise from the bitmap and low resolution nature of the component symbols). There was also a stereo coder (very similar to the first budget one from NRG - the one not knowing left from right) and Medium wave circuitry. The phrase they used was "Everything gets easier with practice, except getting up in the morning!", they were once active on alt.pirate.radio (remember those groups?).

A link. You can already see slating of "veronica" gear at this early time: https://groups.google.com/g/alt.pirate. ... lVro?pli=1

I've got a 30 Watt (PLL 3) TX from Veronica! Which I bought back in 1998. Just fired it up and she is giving out 30 watts.

See the video!

[3metrejim]

I've got a 30 Watt (PLL 3) TX from Veronica! Which I bought back in 1998. Just fired it up and she is giving out 30 watts.

You must have purchased it before the infamous 'Fall-out'. Veronica was the original name, and came from Bradford in Leeds. It wasn't until sometime in the early 2000's that the name changed to NRG. It should be easy to tell if it's an original, just by looking inside (if you know what you are looking for).

There may be some old ad's from old electronics magazines around online with the original name, but I cannot find any as yet.

That's a cool idea, using the old pirate gear as the cover picture for a live stream.

[trancetechnic]

I've got a 30 Watt (PLL 3) TX from Veronica! Which I bought back in 1998. Just fired it up and she is giving out 30 watts.

You must have purchased it before the infamous 'Fall-out'. Veronica was the original name, and came from Bradford in Leeds. It wasn't until sometime in the early 2000's that the name changed to NRG. It should be easy to tell if it's an original, just by looking inside (if you know what you are looking for).

There may be some old ad's from old electronics magazines around online with the original name, but I cannot find any as yet.

It's an original one! Purchased new! I think I payed just over 300 pounds. Had this TX on the Glasgow airwaves many times back in 1998/9.
I've got another PPL3 From the year 2K. The person that tested the board put his name on it! WILL. Short for "William" I take it. Great TX,
can't fault it. I've also got the first PLL board.

Picture -

[3metrejim]

It looks similar, but no balancing transistor in the oscillator. Not sure on that.

Original Veronica Advert, Feb 1998. From EPE magazine (available on the internet archive).

[3metrejim]

Looks like I got the wrong ad, if you read here:
https://groups.google.com/g/alt.radio.p ... 26ZH3TMsJM

[jvok]

I do have some diagrams for circuitry that uses a multiplier with a BGY33 module. It was widely available online once upon a time, and was attributed to 'BiasComms' accodring to the diagram (their diagrams are quite easy to recognise from the bitmap and low resolution nature of the component symbols). There was also a stereo coder (very similar to the first budget one from NRG - the one not knowing left from right) and Medium wave circuitry. The phrase they used was "Everything gets easier with practice, except getting up in the morning!", they were once active on alt.pirate.radio (remember those groups?).

Pretty sure biascomms is Zozo on here

[3metrejim]

Pretty sure biascomms is Zozo on here

Have you seen the old forum alt.radio.pirate ? Sure looks like Bob on there is Albert on here.

https://groups.google.com/g/alt.radio.p ... eAwg7J5joJ

Sound familiar?

https://groups.google.com/g/alt.radio.p ... 1GWRXa_d8J