Heathkit AR-1515

As I wrote earlier my receiver is working fine again.
But I did not replace the 2 big 10000 uF elco's in the power circuit.
Nor did I replace the capacitors in th power amplifiers circuit boards.
The receiver is powered on the whole day since he is finalized from the beginning.
Because everything works fine I wonder if I need to replace the 2 big elco's because new ones are much smaller and difficult to put inside.
Thanks and kind regards
Georges.

If the receiver plays well, then it is not strictly necessary. There is an element of preventive maintenance, however, and if there are any signs of leakage or swelling on the old reservoir capacitors, then you should replace them asap. You can increase the capacity a bit, if that makes it easier to find caps of, or near, the right size.

Sorry for the late response, but there are no signs at all that the big 10,000mf capacitors are leaking or damaged. The receiver again is working fine the whole day long. Even until late at night because the television sound goes around it.
He was working since the early 80's when I finished building it, also about 15 hours a day every day except when we were not at home of course.
It is a very fine piece of electronic art nohum noise and a fine clear sound reproduction, with perfect pro speakers of course.
About 10 years ago I had to replace the dial lamps by led's because finding new mini lamps became hard to find
I hope it will stay this. Way for as long as I live.
Regards.

Just for your interest.
Some weeks ago my receiver (AR1515) sometimes didn't give the L channel anymore or it felt out after some hours, a few minutes later it comes back or it stays out.
So after a while I put him on my workplace and temporarily put an older receiver in his place.
But it took a lot of time before he did the same on my workbench. Everything was okay no defect, nothing, until I though about the muting circuit and yes the relay sometimes didn't made good contact on one of the switches inside.
So, I replaced it with the one I had from another AR1515 I bought years ago for a low price.
The owner wrote that the left power amplifier was damaged
But when years ago that receiver arrived it was very bad packed that there was even a bow in the very strong chacis so my intention to repair it and resell it was gone.
Anyway after repairing my own one I accidentally made a short circuit in one of the output amplifiers, so I had to remove these power amplifier to replace the diode and because of that I also replaced the 6 elco's in both the amplifiers.
But more important my eye's felt on a old technical bulletin from Heathkit I Had in my manual.
That report suggests to replace the power transistors from T.I. by same types of Motorola, reason was a chance of overheating of the T.I. transistors.
So I found 2 Motorola transistors in the damaged receiver and put them in one of the amplifiers.
After 3 hours indeed the amplifier with the Motorola transistors stays totally cool while the other one got warm but not that much at normal output level, what I knew from the very beginning.
But even after 24 hours of operating the L one stays totally cool while the R one was always warm.
Since the other output amplifier of the spare one didn't contain Motorola transistors but some Japanese or Chinees I went to the store and replaced also the transistors of the other channel by MJ11016 type transistors because the Motorola where no longer available.
Now both output amplifiers stay cool the whole day at normal volume level.
Just to be sure I measured both output signals on a scoop and the are perfectly exactly the same in amplitude with the balance in the middle.
It is perfect over the whole audio range from 20Hz to over 20kHz even on different output volume.
It's a long story but maybe someone can use it.
And yes, I measured 2 of the old elco's on leakage and there is no leakage measurable so finally I didn't have to replace them but anyway.
Regards.
Georges

Good job! Great to hear that it worked out for your in the end.

Yes, thanks,
I've finished building it February the 6 in 1981. There is no scratch, not even at the rear panel os site one, it looks like brand new.
Now on the inside it's new also, except the 2 big elco's.
A few years ago I replaced the dial lamps by LED's so it's still a very fine piece of electronic device.
I was even in the ability last week to put extra new rubber feets at the bottom.
When I'll die (hopefully not yet but one never knows) maybe I can tell them to send it to my daughter in the USA
The only thing she has to do is changing the power supply and the deemphasys because when I build it I recalculated the R/C network for 50 micro seconds, Ik the US it's 75.
I hope I can enjoy it for a long time.
Kind regards.
Georges.

Hi,
I'm repairing an AR1515 receiver from Heathkit.
The receiver I bought many years ago in a very bad and damaged condition.
The gaul was to keep it for spare parts for my own.
But mine is perfectly okay since I've replaced some parts.
So I started to repair the other one.
After many working hours, defects in the power supply output amplifiers readout circuit board etc etc.
The receiver is finally nearly working perfect
Only the readout is still a problem.
Only in the morning when I power it on at a station above 100MHz everything is okay, but after about 5 minutes the readout changes from 102.9 to 182.9 but the tuned station stays tuned
Lower then 100MHz there is no problem. The same situation on AM
I replaced IC's measured power voltage and so on, always the same.
Maybe I have to replace all IC's on the counter circuit board.
Does anyone have a solution for it? Thanks
There is also a problem with a shifting tuner meter indication but that's for later.
I'm glad he working but I this is snug.
Thanks.

A few days go, after finishing to replace the display bulbs by LED's and investigatetion on the schematics I discovered that IC-406 was the problem.
When the readout gave a 182.9 instead of a 102.9 I held a cooled metal piece against the IC and the display changes to 102.9
So, I'll have to replace that IC and hope it will be okay.