I was hoping someone may have a schematic for a Kingsley RKR radiogram,

Regards
Vic

Same here. Andrew (TV Collector) said it was probably based on a Philips circuit. It has Philips IF transformers and Philips mustard caps, at least

If it only needs a refurbish and the Monkeys have not been in it, one could muddle through with out a circuit.

Marc

Hi Sue,

Mine had some burnt out parts but I have managed to work out what they were.
The chassis works very well now. Does yours have the same problems? Maybe I can help.

Cheers
Vic

MIne's fine as a record player, but the radio just whistles. I'll get round to it one day. A diagram would help.

Hi

I found one in the local op shop a month ago, and have started this thread to discuss it. I have traced a circuit out and posted in in the thread as a link.

http://vintage-radio.com.au/default.asp?f=2&th=476.

Wow. Thank you so much for the schematic!

I have a Astor Stereogram using all of these tubes, and with a fifth tube which I guess is doing the rectification for DC. I am unsure of the tube # as all markings have come off this tube.

I am looking at doing a modern restoration with the tubes on display, so would need to do a complete rewire. Do you have a better res copy of the schematic? Its rather blurry when enlarged, or is there a better program to open it with (Mac).

Also are you able to tell me what the "L102" components are. I am very new to this.

Once again thank you

I'm back at work on my Kingsley RKR radiogram. The radio's now working properly and sounding good. It seems to have fixed itself after being in the shed a couple of years. So the first problem to solve was the almost complete lack of bass when playing records. I put a BSR TC8S cartridge in because I know these are good, but the sound was as thin as ever, and although the Kingsley's simple tone control can attenuate the treble, it isn't able to boost the bass. I had a look at the circuit of my Pye Black Box, which is a mono table player of the same size but with better speakers and excellent tonal balance, and it has a 0.01μF capacitor and a 15K resistor wired in series across the pickup input. So I tried this arrangement with the Kingsley, and experimented with different resistors and capacitors across each PU input until the tonal balance was good in the middle of the tone control's adjustment range. The right combination was 0.01μF in series with 1.2K. I'm very happy with the sound now.

The next step is to look at the HT smoothing capacitors, which are getting very warm. I'll have to pull the chassis for this. I will draw up a circuit while I'm doing this and check it against the Philips and the other circuit posted here. I'll be back!

The filter caps when electrolytic require a certain amount of leakage to maintain the layer of oxide that is the insulator inside. This layer is lost over time when not used and NOS (2years +) here is normally put onto a reformer to check viability & restore the layer.

The fact that they are getting hot will relate to them drawing excessive current and every electrolytic should be replaced: Watch the voltage rating & some 450V ones are crap.

Firing up Radios & Amps etc. which have been sitting for a long time unused (or abandoned as they failed) is unwise. Those electrolytic's can explode, burn out the rectifier, or transformer due to overload.

Marc

I've just tested them, and I was surprised to find they are still good; after reforming, the leakage was only 100 microamps at the rated 350V, and the capacitance is within 10% of the rated 50μF. They are axial Elnas, normally a quite reliable type. Maybe the problem is the selenium rectifier.

I'll continue this in "Tech Talk", this is the wrong thread for problem solving.

Selenium rectifiers can be an issue and it would not be unusual for one to fail, often in a cloud of toxic waste. If there is AC getting into the caps, that would cause the filter caps to get hot.

What needs to now be known is the current consumption of the sets B+ and that's where the schematic may be useful? Australian manufacturers / AORSM's did occasionally have a weak moment and actually put current & voltages on them.

It should be noted if it is a half or full wave rectifier. The purpose of the exercise being the result of the Silicon diode being more efficient: Series resistance will need to be added in B+ if they are used?

This is not really the right area for fixing but the problem is, if there is more than one post in different areas on the same set, info can get lost.

It is indeed, better, to open another thread for a different radio.

Marc.

OK Marc I'll keep going here, at least it's got Kingsley RKR in the title.

Yes, it was the selenium rectifier (full wave) that was faulty. I made up a new rectifier with four 1N54004 diodes on a tag strip. Now the capacitors stay cool, the transformer only gets mildly warm, and the HT has gone up from 160V to 250V. Consequently, the volume is much stronger. Just some work to do on the cabinet do now.

I've nearly finished the circuit diagram. It is a Phillips circuit with some minor modifications.

Just watch that voltage it could strain a few friendships if its wrong. The cap rating may well need to go that of a 5Y3 as you will get quite a surge on startup with heater valves (close to twice set working volts). Do measure.

You may also draw too much current for the transformer & some resistors. The value of things like cathode resistors can give an indication of what voltage it was meant to run on. Backbias resistors are also good indicators. If there is a Valve element voltage chart, all the better.

Which Philips?

Marc

The circuit is very similar to the Philips 227C, except the audio valves are 6GW8 instead of 6DX8, and the tone control isn't part of the negative feedback loop. The HT for the 227C is 228V, so maybe 250V is a bit high.

Kingsley RKR 1967 Circuit Diagram

(This circuit diagram is edited from a Philips 227C. The same chassis was used in the Kingsley KRG514 radiogram.)

Document uploaded to Post 14.