AKG P8 repair possible? - UK Vintage Radio Repair and Restoration Discussion Forum

Bufo Bill · 25th Jun 2021, 10:05 pm

Hi, today for your consideration is an AKG P8 pick up cartridge. I bought this as a speculative purchase a few years ago on ebay.
One channel was very weak so it was put on "the shelf of projects yet to be" and left until money could be found to repair it.
That day has arrived, so I measured the resistance of the coils; white to blue has roughly 1k Ohm, while red to green is open circuit.
So possibly a simple dry joint?
Is 1kOhm high for a coil in a moving iron cart?
One thing that has changed in the time since I bought this is my confidence in having a go at repairs. Is this an instance where I can effect a repair myself, or am I well out of my depth? The plastic shell seems to be openable with a couple of little tabs, but the tiny size of the coils worries me; will a regular soldering tip be too large and fry everything, or is that what was used originally?
I would love to be able to say that I put one of these back into working order, but what would be better would be to be able to say I did it with my own two hands (and a lot of rude words, probably).
So basically my queries are as follows:-
Is my diagnosis of cold joint feasible or are catastrophic failures with these now common?
Is this something I have a good chance of succeeding with, or just spend the cash and get an expert in?
Cheers, and sorry for rambling!

Ted Kendall · 26th Jun 2021, 7:49 am

It's a long time since I saw a P8, so I can't recall whether the contact pins are hollow. If so, carefully running solder down the inside of the RH channel pins may effect a cure. This is a job for liquid flux, a hot iron with a small bit, swift action and nerves of steel. You are likely to get one shot at it. I'm not sure who would take this on, if you decide to farm it out, as success is by no means guaranteed - you could try Expert.

Bufo Bill · 26th Jun 2021, 5:45 pm

Cheers Ted, Expert were the guys i had in mind.
Not a good idea to disassemble then.
Cheers from Bill.

Ted Kendall · 26th Jun 2021, 6:08 pm

Probably best not to, unless you rebuild watches for kicks! Nice cartridges, though.

Bufo Bill · 26th Jun 2021, 6:17 pm

Funny you say that Ted, I have always been fascinated by watches. I could probably take one apart, it's the putting it back together where my knowledge and abilities fail!
Bill.

25th Jun 2021, 10:05 pm	#1
Bufo Bill Heptode Join Date: Jan 2016 Location: Wolverhampton, West Midlands, UK. Posts: 777	AKG P8 repair possible? Hi, today for your consideration is an AKG P8 pick up cartridge. I bought this as a speculative purchase a few years ago on ebay. One channel was very weak so it was put on "the shelf of projects yet to be" and left until money could be found to repair it. That day has arrived, so I measured the resistance of the coils; white to blue has roughly 1k Ohm, while red to green is open circuit. So possibly a simple dry joint? Is 1kOhm high for a coil in a moving iron cart? One thing that has changed in the time since I bought this is my confidence in having a go at repairs. Is this an instance where I can effect a repair myself, or am I well out of my depth? The plastic shell seems to be openable with a couple of little tabs, but the tiny size of the coils worries me; will a regular soldering tip be too large and fry everything, or is that what was used originally? I would love to be able to say that I put one of these back into working order, but what would be better would be to be able to say I did it with my own two hands (and a lot of rude words, probably). So basically my queries are as follows:- Is my diagnosis of cold joint feasible or are catastrophic failures with these now common? Is this something I have a good chance of succeeding with, or just spend the cash and get an expert in? Cheers, and sorry for rambling!

26th Jun 2021, 7:49 am	#2
Ted Kendall Dekatron Join Date: Jul 2008 Location: Kington, Herefordshire, UK. Posts: 3,675	Re: AKG P8 repair possible? It's a long time since I saw a P8, so I can't recall whether the contact pins are hollow. If so, carefully running solder down the inside of the RH channel pins may effect a cure. This is a job for liquid flux, a hot iron with a small bit, swift action and nerves of steel. You are likely to get one shot at it. I'm not sure who would take this on, if you decide to farm it out, as success is by no means guaranteed - you could try Expert.

26th Jun 2021, 5:45 pm	#3
Bufo Bill Heptode Join Date: Jan 2016 Location: Wolverhampton, West Midlands, UK. Posts: 777	Re: AKG P8 repair possible? Cheers Ted, Expert were the guys i had in mind. Not a good idea to disassemble then. Cheers from Bill.

26th Jun 2021, 6:08 pm	#4
Ted Kendall Dekatron Join Date: Jul 2008 Location: Kington, Herefordshire, UK. Posts: 3,675	Re: AKG P8 repair possible? Probably best not to, unless you rebuild watches for kicks! Nice cartridges, though.

26th Jun 2021, 6:17 pm	#5
Bufo Bill Heptode Join Date: Jan 2016 Location: Wolverhampton, West Midlands, UK. Posts: 777	Re: AKG P8 repair possible? Funny you say that Ted, I have always been fascinated by watches. I could probably take one apart, it's the putting it back together where my knowledge and abilities fail! Bill.