First station to use PLL?

[jvok]

I know PLLs become a thing in the 80s - early 90s when digital tuners took off, but some stations were still using VFOs well into the 90s. Also wouldn't be surprised if the odd station in the 70s used one

Anyone know what the first (pirate) station was to use a PLL rig? Who the builder was? Bonus points to anyone who can link to the oldest published PLL design

[teckniqs]

Albert is 100% gonna say it was him for sure, ok maybe not then now I've just said that. haha.
....Nah only joking of course, it's guaranteed that he still will.

[Albert H]

My first PLLs were in 1975 or so. The very first ones were for 6.3MHz shortwave, with a 4MHz reference rock, then I made loads for MW frequencies, using a 4.608MHz or 2.304MHz reference crystal (which easily divides by powers of 2 to 9kHz) and the crystals were originally used in baud rate generators. The logic I used in those days was all TTL, and my phase comparator was a pair of bistables in a 7474 and a NAND gate. The principle had been written up in various technical journals in the late '60s, and I was pushed into their use by the expense of getting crystals cut. My reasoning was that the standard crystal from Farnell and a handful of TTL was cheaper than getting crystals cut, and made changing frequency easy and accurate. The first PLLs were built on "Veroboard" stripboard, but later we got PCBs etched as other stations wanted to use the technology.

Again, my first PLLs for Band II used the early Plessey ECL divider ICs, particularly the SP8629, which would divide by 100, bringing the Band II frequency down to around 1 MHz, which could be handled by ordinary CMOS. I found another Plessey 8-pin chip (SL560) which was a little VHF amplifier in a DIL case. The IC had both the base and the emitter of its first transistor available on the pins, so it was easy to use it as a Colpitts oscillator with a self-contained buffer amplifier!

Not much later, the first 74HC logic ICs became available, and I came up with a really simple PLL for any frequency up to around 70 MHz. My Band II rigs then had to use doublers to get to the output frequency which was no bad thing, because as RF output power rose, RF feedback problems to "at frequency" oscillators became an issue.

My typical early 80s PLL was a 74HC4060 as the reference oscillator and reference divider usually with a cheap 4 MHz crystal. I used the "HC" version, because they could easily be programmed with a resistor from the 5V supply to the Reset pin, and then a "wired-OR" gate connected to the Reset pin using 1N4148 diodes. The 74HC4024 would easily divide 70 MHz by 2, 4, 8, and further. I used that as - effectively - a prescaler. The presettable divider - to select the Band II frequency I wanted - was a 74HC4040 also programmed by diodes. Sometimes I'd use the 4046 phase comparator, but found I got better results (and an accurate lock / unlock indicator) using a 74HC74 and a 74HC00 NAND.

Again, I got PCBs etched, and my basic exciter in those days used a BSX20 oscillator (or 2N2369A) , BSX20 buffer / splitter, with the collector driving the logic, and the emitter providing a low impedance drive to the doubler stage. There was a BSX20 doubler, followed by another BSX20 filter stage (to get rid of any oscillator residual). This drove a 2N4427 to around 800 mW, which was the power output of the module. We refined the layout, over several iterations, and got the size right down.

That exciter topology is still in use all over the world!

[Albert H]

The first FM station in the UK was probably RFL in the late 70s - Myers built a number of PLL rigs back then!

[Shedbuilt]

Myers built a number of PLL rigs back then!

I saw a Band III link Tx he'd built, back in the early 80s. From what I remember, I think it was a heterodyne affair, with the PLL VCO mixed with a crystal oscillator, and the product driving a chain of multipliers.

[Albert H]

That was one approach he used. He also made use of the early Plessey ECL prescalers (as I did) and did his PLL at around 1 MHz with ordinary CMOS.

My later Band III link rigs used a VCO at around 50 MHz, then cascaded doublers to get up to 200 MHz. Some of the early ones used the Plessey ÷100 ECL chip from a 100 MHz VCO and a single doubler stage. When the Plessey chips started to get scarce (and more expensive), I started to use the 74HCT4024 as a prescaler to divide a half-frequency VCO by 4 or 8 and then a 74HCT4040 with diode programming for the adjustable divider. The phase comparator was a 4046 or, later, a 7474 and 7400 which gave really good lock detection.