I am happy to say both my Kriesler beehive and Peal mantel radio's which both were very quiet and scratchy even after re-capping are now great performing loud radio's after I replaced most of the resistors, the difference is astounding! I only have one "fixed" radio now which is still problematic, being quiet and scratchy, one Kriesler 11-80, which I am planning to go over again all of the soldering I've done and keep replacing resistors, some out of spec ones I've done, but some closer to the front end I haven't done as yet, may be the culprit.

One peculiar thing I have noticed, not sure if anybody else has noticed this, but after re-capping and re-resistoring.... When first powering up the radio, there is only a small, unremarkable improvement, which is a bit of an initial disappointment, Only exception being the Astors I have, two BPJ's and an NJ, I'll describe next, but all of the others a bit ordinary and disappointing at first, but after running for an hour or so, shutting down and re- powering up a day or two later, they suddenly work amazingly, as if the valves must "re-learn" the correct parameters provided by restoring the correct capacitors and resistor values, almost like they "grow" into the repair. ??? Is this normal? Regardless I'm happy with the result, great radio's these are now! It's really the resistor work which makes the difference, high resistors really drag down the performance!

Now the Astor NJ roared into life after repairing and is so amazing, the sound is just larger than life, bass response is just unbelievable! But one of my BPJ's sounds great at first but over an hour or so grows steadily quieter, I end up with it on full volume and it ends up fairly quiet and the cabinet quite hot, so I'm guessing, maybe there's a resistor going high, maybe heating up, then cooling down to normal again?

Then one of my B-15 Radiolas, the "Westinghouse" is a cracker! It's had the larger speaker, 4x8" instead of the original 4x6", modified to fit in the case, it's 4 watts 15 ohm instead of the original 3, but the transformer is juicier and I've got 230V from the rectifier, to the amplifier valves and coils instead of the normal 185V and it is ridiculously loud, I have it in the laundry with the back door open at two thirds volume, otherwise it distorts, but at this level it's a hot little garden radio when we're outside weeding, gardening or just enjoying the back yard. It's loud and very clear throughout the back yard! We've had it on for hours and it hasn't got hot or blown up, or shown any ill effects from the higher voltages, it's definitely a souped up unit!

Hello JamieLee.

I can't say I've noticed that effect myself, and I have restored 100s of radios.

The problem with your BPJ could be a valve. They can have grid emission, which gets worse as the set gets hot. Monitor the AGC line to see if it gets less negative with time, also look at the voltage on the output valve control grid. It is not a good idea to operate the set if the output valve is suffering from grid emission. The rectifier and power transformer will be endangered.

Ok thank you Sirwin, I definitely want to rule that out if it can harm the tranny! Funnily, when I restored it, I replaced that (6m5) as I had 2 NOS ones I bought from ebay! But with NOS I suppose we are only taking somebody's word.... Thank you for your input, cheers.
Here's another, a B-15 radiola, I replaced all ppaper and electrolytic caps and most resistors, but it still wouldn't work, so I'm sitting there with it all powered up, chassis upside down in the case, on the kitchen table and I have my multi-meter with an alligator clip on the chassis, I'm probing valve pins and getting all the right voltages, then whilst on the grid of the detector, I hear faint music in the speaker which over five seconds got louder and louder and the radio was working fine, I did notice the first RT coil can, the solder had come loose from the can to chassis, and wobbling the can caused harsh noise, I couldn't re-solder it as my soldering iron isn't hot enough, so I soldered a wire to the can's solder blob, which I soldered to earth, no more noise! It's funny I got to test our Clipsal safety switch, as I hd turned it off earlier having no luck getting it going, forgetting it was still plugged in, picked up the chassis and nearly jumped out of my skin and all the lights and the TV went out! The wife was cross about having to reset the clock lol, definitely a must those RCD's t least I didn't stick to it and end up burned, like I did a few years back from a faulty guitar amp!

There are things I do irrespective of it being a commercial valve radio repair or not, once I decide its viable. One is to make sure all resistors are checked and if it an aged set and especially one that has been sitting a while, is to replace any wax paper caps & electrolytic ones.

The resistors in the name of efficiency and saving grief, when it fails to fire up, should be tested & replaced if out of spec as you go. Rework risks damage and fixing as you go enhances the chance of it actually running first try.

I always monitor the B+ rail on startup & if it does not go according to plan I can quickly hit the kill switch.

Normally I burn test them for around 3 hours before making final adjustments, statistically most dodgy components should have failed by then.

The sets IF should be realigned, before touching any of the front end adjustments. The Signal Generator & an Oscilloscope are a formidable team for finding distortion & lost signal.

Yes I do that too now Marcc, Check resistors as I replace caps, and replace too if high, and they nearly always are and often considerably, even though the set still works.

I have an extension lead with a 100w incandescent globe in series on the + for first time power-ups, this way I can reasonably safely test if a set is working at least in some capacity before replacing bits, which I will do now routinely in any case, but with the bulb, if it lights up, I just power off then start replacing bits, all paper and electro's and bad resistors, then power up through the globe again just in case!

I don't have a signal generator yet and have thus never attempted a realignment, (I'm still clueless!) fortunately so far, I haven't really needed to, having got good results from replacing capacitors and resistors, however, realignment is definitely a process I want to learn how to do!