I've had this radio for about 20 years. Original pristine condition.

When I got it I had to replace a shorted 20μF electrolytic and repair a corroded wire on the speaker. At the time I bought a few NOS speakers for it on FleaBay but fixed the speaker before they arrived.

I use 8 x alkaline 216s snapped together and a couple of alkaline D cells. The 8 x 216's are a perfect fit in the 67.5v battery bay
These normally last several years when used for about half an hour of a morning.

About a year back I finally replaced the speaker which had gone OC again and recapped it while I was at it.

Performance has degraded slowly over the last year. I thought it was just batteries, I can't remember when I last replaced them - but they measured 57 volts and 1.36 volts which wasn't low enough to explain the distortion that was so bad it made speech unintelligible

So, this morning I finally got around to investigating it.

Back bias resistor measured 1300 ohms, should be 800. Replaced it with no effect.

Checking voltages around the 1S5 1st audio. Absolutely zero anode volts! So I replaced the 1m resistor anode load resistor and got cleaner sound than I'd ever heard on this radio before!

What gets me though, is how I could get quite loud but very distorted audio with a completely open anode load resistor.

Ian you have inspired me to look at mine.
Cannot see how 8 X 216 batteries are going to fit without a modification to the B cell holder.
Let alone clipped together using existing connections.
Have tried several ways, must be getting old....
Maybe an image please.
JJ

Yes it's a bit like a Rubiks Cube.
You need 2 pairs of snaps, one for the output and one for a link between the two banks.
Send me an email!

I have one of these, which I have not used for a very long time. Don't worry though, there are no batteries in it leaking white powder everywhere.

Back in the 1990s when I last powered it up I found that using all eight batteries made the set sound a bit garbled and I removed one battery for 63V which it seemed to like better. Of course, back in those days, replacing the capacitors and what-have-you wasn't a regular pre-requisite to getting a set going again like it is these days and at the time I felt that due to it running on batteries it would have seldom been used.

I should give it the once over and see if it'll go again. The valves should still work.

‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

I can see now how to get eight 9 volt batteries in, but would have to solder them together.
Cannot see how they could be clipped together.
And have just found that the rubber dial/gang drive is perished and does not work.
So, need to find something to do the job. Not easy to get this section apart either.
JJ

You solder nothing onto a bank of 9V 6LR61's. You salvage a dead one decapitate it and salvage the terminal plate. You then cut it in half and they are the battery clips. Soldering a wire to them is interesting.

You then acquire some wide tape and something to cut it with. This is required to hold them together. One then gets the required batteries and joins them together one up one down in a line.

I did publish /was published; That method somewhere ages ago.

Marc

With a tight squeeze, it is possible to link 9V batteries by directly linking them but that won't work on this radio as there is no room for it. On mine, I have included seven normal battery snaps, wired in series. It's a little messy but it works none-the-less. The A battery is two D cells in parallel. These get replaced far more often than the B battery.

‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

Not enough room for those sorts of terminal ideas Marc.
With tinned copper wire soldered directly and made a neat pack.
Found rubber drive wheel for tuning gang, checked resistor tolerances, checked all black AWA caps and did not bother to change any.
Radio working fine after goodness knows how many years.
Ended up with seven 9 volt batteries for neatest job.
JJ

QUOTE: Checking voltages around the 1S5 1st audio. Absolutely zero anode volts! So I replaced the 1m resistor anode load resistor and got cleaner sound than I'd ever heard on this radio before!

That resistor was likely drifting higher in resistance and then went open circuit. Which would explain the distortion. Not sure how any signal would make it through the pentode with zero plate voltage. Maybe electrons ate attracted to the screen, and some electrons miss the screen and hit the plate? More likely the plate resistor didn't go completely open circuit, but went to a high enough resistance that your VOM thinks it's an open circuit. Like 30megohms.

It's all in the way you clip them together. Marc has the basic idea, maybe it needs a video....

You most definitely CAN fit 8 x 216s in an unmodified 450p holder. I have two of these radios and both will take the two slabs of 4.

Apart from the wires to the output clip and the "bridge" clip that connects the two slabs in series, you don't need to solder anything and you can replace the batteries without soldering.

Wa2ise, you are spot on! Out of curiousity I took the "o/c" 1m resistor to work where I hooked it up to a 110 volt power supply and a microamp meter. With 30 volts applied it passed 1uA - presto, that's 30 megohms!

With the 1S5 running at zero bias (grid leak) it will saturate at 1uA. Negative signal peaks cut it off and the 30 megohms is enough to pull the plate high on those peaks. No wonder it sounded horrible!

Problem solved.
The battery holder in mine had been bent, And I can only conclude to perhaps stop old original battery from moving around.
The end near the speaker transformer was bent in.
It did not take long to solder 7 batteries in and performs well.
Next time will use two slabs of four as Ian has found.
JJ