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Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE!

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Old 13th Sep 2020, 10:34 am   #1
Nanozeugma
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Default Hacker Mayflower II.

Bought in Rotherham and brought home to London, sitting on the round tuit pile for a couple of years, finally got round to fixing it.
Cabinet in pretty decent condition I'm pleased to say as woodwork is not my forte.
Initially it motor boated like crazy, very low frequency, fit to pop the speaker cone given half a chance.

It had obviously had attention before, this appeared to have been limited to replacing the odd coupling cap, crudely restuffing the main reservoir / smoothing can, changing a single ECL86 cathode bias resistor (220R,) and replacing the on-off volume control with a Radiospares example (1 Meg log law /double pole switch.)

So in we dived. Hacker had thoughtfully (!) wrapped component leads tightly around their tags so every component was a swine to remove and test.

All the non polarised and electrolytic caps leaked - the red tubular ceramics were fine, as expected. The bodged main smoother was replaced.
Virtually every resistor was out of tolerance, some by as much as 50%. The 220K ones were particularly bad for some reason.

So a blanket change was the order of the day.
Only one avoidable error, the solder hadn't "stuck" to one end of R26 (220K) for some reason, so on first test it was silent. V6a anode was at 208 volts and the cathode at 5.6 volts virtually floating.
This resolved it worked very nicely.
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Old 14th Sep 2020, 11:47 am   #2
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Default Re: Hacker Mayflower II.

A very worthwhile restoration. These are one of the best sounding radios of this class.
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Old 14th Sep 2020, 12:35 pm   #3
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Default Re: Hacker Mayflower II.

Yes, well done.

As Simon's said, these are lovely sets; well-engineered, well-built, and lovely to use and listen to. My late grandfather bought one secondhand in the late 1970s, got a great deal of pleasure from it, and I still use it now.

Some might have been more conservative, but like you, I would have changed a similar number of components.

How about a picture of the chassis? They do look lovely, sitting under the huge Goodmans LS.

Nick.
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Old 14th Sep 2020, 5:37 pm   #4
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Default Re: Hacker Mayflower II.

Quote:
Originally Posted by Nanozeugma View Post
Hacker had thoughtfully (!) wrapped component leads tightly around their tags so every component was a swine to remove and test.
That's hard work. The procedure I use is to snip the faulty component leads as close as possible to their bodies, then I wind the leads on the new component into a small, tight 'tube' using small round nosed pliers. I then insert the 'tube' over the existing leads and solder in place. That way, you don't have to spend ages trying to remove every last drop of solder from mounting tags and untangling the leads of components - perhaps overheating them in the process. The original soldering on the soldering tag remains solid and untouched. Photos attache of some I've done today on a Philips set
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Old 14th Sep 2020, 6:17 pm   #5
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Default Re: Hacker Mayflower II.

I do it like Nanozeugma most of the time, especially on sets like Hackers which are a joy to work on because of their nice layout, and which deserve to stay looking smart under the chassis. Your example, Steve, looks like a Grundig or similar... great performers, but what a rat's nest underneath.

However, Steve's point about the risk of overheating (or mechanical damage) during tricky de-soldering work is very valid, so I do it Steve's way if access is tricky and with heat-sensitive components (which includes tags which have PVC-insulated wires attached to them; molten and shrunken PVC insulation looks horrible!).

Here's a pic of one of the tag boards on a very sad Hacker which I restored recently. It had been run in an overheated state for long periods, and lots of components were utterly cooked! Note the way I've attached a little polystyrene cap underneath (and in parallel) to the 10K resistor - similar "tube" technique.
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Old 14th Sep 2020, 6:23 pm   #6
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Default Re: Hacker Mayflower II.

And here's another pic from the depths of a Cossor VHF set's chassis, using Steve's "tube" technique on the lower connection, because there simply wasn't good enough access to do it any other way, without major (and risky) dismantling.
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Old 15th Sep 2020, 11:51 am   #7
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Default Re: Hacker Mayflower II.

Quote:
Originally Posted by Nickthedentist View Post
How about a picture of the chassis? They do look lovely, sitting under the huge Goodmans LS.

Nick.
As requested, I'll have to upload in two bites.
This is "before".
Note the "superbly" restuffed main reservoir / smoother...! The white stuff is some sort of expanding foam.
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Old 15th Sep 2020, 11:53 am   #8
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Default Re: Hacker Mayflower II.

Quote:
Originally Posted by Nickthedentist View Post
How about a picture of the chassis? They do look lovely, sitting under the huge Goodmans LS.

Nick.
This is "after".
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Old 15th Sep 2020, 12:16 pm   #9
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Default Re: Hacker Mayflower II.

Wow, that's more like it. Quality job!
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Old 15th Sep 2020, 1:38 pm   #10
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Default Re: Hacker Mayflower II.

Quote:
Originally Posted by Nickthedentist View Post
Wow, that's more like it. Quality job!
Thank you

In regard to Steve's (and your) comments regarding removing *everything* back to the tag - or not...
The point made about the potential problems with heat is well made and well taken. On the odd occasion where PVC insulation has shrunk back and become unsightly, I simply replace the cable run as well
Although I still persist with removing everything (might be OCD, I've been accused of it,) I did experiment with Steve's methodology when restoring a Heathkit AFM-1 recently. I found you could make a nice "coil" on the end of your replacement component using a sewing needle and miniature needle nosed pliers.
I have a Telefunken chassis to restore when I get time which is, as alluded to, an absolute rats nest underneath (and on top as well, if truth be told.) For that one, I think the "coil" method will be followed
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Old 15th Sep 2020, 4:06 pm   #11
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Default Re: Hacker Mayflower II.

Did you re-stuff Bridge Rectifier, or is it original? When I did my RV14 some years since I bolted a modern replacement bridge to the chassis, and added a resistor.

John.
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Old 15th Sep 2020, 5:35 pm   #12
Nanozeugma
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Default Re: Hacker Mayflower II.

Quote:
Originally Posted by 60 oldjohn View Post
Did you re-stuff Bridge Rectifier, or is it original? When I did my RV14 some years since I bolted a modern replacement bridge to the chassis, and added a resistor.

John.
Hi John,
The Selenium rectifier is original. I viewed it with suspicion, given that the original reservoir / smoothing can had obviously gone to meet it's maker and been replaced - after a fashion - before I got the radio.
However, it proved to be sound and puts out bags of HT which does not collapse as the valves draw current.
So I left it alone.
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