Printed Circuit Board Valve Radio

[wireless_paul]

Hello.

Fancy obtaining some printed circuit valve radios. All mine are point to point wired and not sure what models were made with printed circuits?

Would prefer British made and perhaps with VHF but not too bothered.

Thanks.

Paul

[Wellington]

Blimey - most people run away from anything which features valves and PCBs. I thought there was already a thread somewhere about when PCBs first started appearing in radios, but I couldn't find it.

Just searching around has revealed the Marconiphone T69da, which features here and here (good photos in both these threads); the Marconiphone T89da; Philco 102; Ferguson 627U; Cossor 1200U & 1201U. I suppose there are loads of others. You'll find that a lot of these models had 'clones' under other brands. For example, the link above for the Cossor 1201U says that it is virtually the same as the Philips B2G05U and the Stella ST112U.

Looks like the PCBs were coming in around 1960. You should be able to find a decent example at not too high a price, I would've thought. Some of the designs from around that time are quite nice, too.

Good Luck!

['LIVEWIRE?']

Paul, you may not be intersted in Battery Powered Radios, but the Mark 2 Ever Ready Sky Queen was built using a Printed Circuit Board
They were MW/LW only and used the '96' range valves, power being a B136 Battery (90v HT + 1.5v LT.). We had one around 50 years ago, no idea what became of it, and I haven't seen one since then

[Glowing Bits!]

The Pye VHF2D has a PCB for the main sound output, this set is from the late 50's.

[David G4EBT]

My vote would be for the little Pye R33 table radio, (MW/LW only), produced in 1964, well towards the end of the valve era.

It has some interesting features - it used a PCB to reduce point to point wiring, which makes voltage and resistance checks much easier as the PCB-mounted valveholder connections and other components can be accessed from the top of the chassis. Unlike many small radios, it doesn’t use AC/DC techniques which obviates the need for a mains transformer but have heat producing mains droppers (a la DAC90A). Instead, it uses an auto transformer, (no secondary – just a primary tapped at 66 Volts for the series heater chain). Thus, the HT is direct from the mains, so the usual precautions about live chassis apply. When working on such receivers, I always use a mains isolating transformer – I’m too young to die and too old for nasty shocks!

The set uses only three valves – UCH81 Frequency changer; UBF89 IF amp, detector and AGC, and UCL83 AF Amp and output. For rectification, it uses a small contact cooled metal rectifier, which curiously, is referred to as ‘V4’. The UCH81 and UBF89 have 19V heaters – the UCL83 is 38 Volts (all at 100mA) making a total of 66 Volts for the heater chain.

It’s clear that some of the design features - such as the use of an auto-transformer, metal rectifier and PCB had an eye to costs – perhaps in the face of competition from 'the land of the rising sun', but this also helped keep the set compact, and overcame the heat problems that would have arisen with a mains dropper and a valve rectifier, given that the cabinet is plastic, though being maroon, looks similar to Bakelite.

By 1964, the transistor era was well established - the Bush TR82 series was launched in 1959 - so this little Pye was perhaps on of the last valve models to go into production.

Beauty is in the eye of the beholder, but I think it’s an attractive little set which deserves its place on my now cramped display shelves and it performs well too.

I rather like little sets such as this, the Murphy 198, the KB Toaster and the Polish Figaro.

[Vicboduk]

For a small table top model you could try the KB xx10/20 Minuet series . I think all share the same plastic case.

KB OB10 (1957) - AM only, MW & LW
KB PB10FM (1958) - FM only
KB QB20 (1959) - AM/FM 3 Bands

Vic

ps. Paul has some pictures here

[mole42uk]

Heathkit FM-4U, FM only, there is an add-on stereo decoder but they're like hen's teeth

Heathkit AFM-1, LW, MW, SW, VHF-FM. Nice sets, if built well.

Both are tuners only, I have several of each, some work better than others.

[sentinel040]

There is GEC made VHF only set, whose number escapes me at present, that uses a vertically mounted pcb.

Ian

[crackle]

How about these 2 as well KB RB10 "Gavotte" it is a beautiful shade of duck egg blue.
and KB Nocturne

Mike

[marconi_pete]

I'd recommend the Marconi T69DA. It Has MW, LW and VHF up 100mhz. It also has a reasonably good sound output for a valved set. The cabinet is a lovely maroon and has a cream grill. I've also managed to modify The VHF band on mine to stretch to 107mhz.

[Hybrid tellies]

That Pye R33 sounds nice. Another mid to late 1950's valved set that uses a pcb is the HMV 1376. It's not the smallest set but has an attractive and slim cabinet, uses the usual U series valve line up, and despite using droppers does not seem to run to hot. With its reasonable sized speaker it does sound nice especially on VHF.

[Phil G4SPZ]

Originally Posted by 'LIVEWIRE?'

...the Mark 2 Ever Ready Sky Queen was built using a Printed Circuit Board...

So was the Sky Countess, a very easy set to work on.

I actually think it is easier to replace components on a PCB than in a conventional chassis.

[wireless_paul]

I actually think it is easier to replace components on a PCB than in a conventional chassis.

I believe they are easier to work on and dare I also suggest that they might even be more reliable. This could be because by the time printed circuit boards came in, that component quality had also improved?

My Ferguson Radiogram, purchased new by my parents in the early 1960s is still going strong.

Not used so much nowdays, but in the first 15 years of its life used every day. Only two new components in that time, the mains transformer and the electrolytic (that I believe did the damage).

Paul

[emeritus]

Among the collection of 1950's leaflets collected at various 1950's Radio Shows that I inherited from a colleague at GEC when he retired, is a summary of the manufacturers that were using transistors and printed circuits in their domestic products at the 1957 Radio Show. Specific models are not mentioned unfortunately, but I thought it might be of interest.

[marconi_pete]

It's an interesting read thanks for sharing it. I'd love to see some of those leaflets.

[jay_oldstuff]

The only thing I would say as I've had it on a couple of my valve pcb sets namely an am only Philips bu~something and a VHF only ultra is the pcb becoming conductive around components that run hot causing a number of interesting faults, no where near as much of a problem as found on some pcb based tv's I've played with but something to bare in mind non the less. Surgery to the pcb with a dremmel is sometimes the only cure.

Jay

[crackle]

Not to mention the copper lifting very easily on the early PCB's, I hate them to work on, I find them very difficult to follow the circuit if there is no component layout diagram available. I much prefer a point to point hand wired radio.

Mike

[Phil G4SPZ]

At the risk of going off-topic, successful work on PCBs requires a modicum of care plus the right tools, including an appropriately-sized and rated soldering iron, a solder sucker and good quality de-soldering braid. It's easier in my experience to achieve an 'invisible' repair on a PCB than on a wired chassis!

[AC/HL]

Please keep on topic, suggestions for suitable models.
Feel free to start a new thread on the servicing of PCBs.

[Phil G4SPZ]

Sorry, Bill. Done, see here.