AR88D Dead !!

[ms660]

Colin, I said that 80mA is quoted in the manual, I think I was wrong I think I must have picked that figure up from here at sometime:

http://www.qsl.net/w2vtm/88/Getting%...ur%20AR-88.pdf

I think the external PSU pack is rated at 90mA according to the EMER manual.

Yes 6V6 was a common job.

Lawrence.

[frank rabbets]

My thanks to you all again. Colin my thumbnail picture shows the caps I put in together with a wiring diagram drawn on paper put in next to them. Do you mean the caps might be handed ? They are not electrolytic. The set was silent before.

Lawrence the 3 caps are 4.7uF instead of the 4.0uF recommended. They are 630 volts each. I've changed all the caps you quote together with all 6 bathtubs.

I don't think I have any paper caps left. Most of the small plastic ones have "solar" on them. I cracked one of "those" solar open to find it was ceramic. I also opened one with "micamold" on it and that too was ceramic.

I think my set is totally original. The soldering is all very neat with good "one hit" joints. The harness is faded cloth but underneath this cloth is a very tough black plastic coating.

The set works well. The hum is a bit annoying but I can live with it as long as no damage is being done.

[frank rabbets]

I decided to empty the original block and put the new smoothing caps inside to reduce hum. Amazingly one of the original caps was not connected properly. The wire may have been inside the brass tube which connects it to the outside world but it certainly was not soldered to it. The stick points to the bare wire.

[turretslug]

I've just heaved my AR88 inverted to double-check my recollection of the block connections- and in fact the junction of C96 and C97 (to HT centre tap) is actually connected to terminal 4 in the post 37 diagram, not terminal 5, with their other connections going to terminals 3 (for C96) and 5 (for C97)- sorry! That should help with the hum.... I'd obviously remembered them as they would "logically" (symmetrically) be, rather than their actual connection. Silly thing is, I've probably got the block rebuild details filed anyway. Tsk.

[frank rabbets]

Ah thanks very much for taking the effort to explain that to me. With my limited capability I would have had to dissect the wiring harness to double check my connections. I'll report back. The hum is there still with the caps inside but it should only take an hour to rewire.

[frank rabbets]

No hum now thanks Tsk. Just resistors to go through now and finished. I thought I would cheat and just swap the wires but that would not be good practice.