UK Vintage Radio Repair and Restoration Discussion Forum

UK Vintage Radio Repair and Restoration Discussion Forum (https://www.vintage-radio.net/forum/index.php)
-   Vintage Audio (record players, hi-fi etc) (https://www.vintage-radio.net/forum/forumdisplay.php?f=14)
-   -   Hacker GP42 and AL42 restoration help (https://www.vintage-radio.net/forum/showthread.php?t=157844)

dekor8tor 12th Jul 2019 8:10 pm

Re: Hacker GP42 and AL42 restoration help
 
Ok Frank i will change what Michael advises and do a re check
Many thanks

Nuvistor 12th Jul 2019 8:26 pm

Re: Hacker GP42 and AL42 restoration help
 
If you still have voltages that are a long way out after replacements are fitted. You could measure the cathode voltages of the pentodes, they are 1.4v and 4v at present. Swop the valves over, if the low voltages follow the valve then it’s a sign that the valves are low emission.

dekor8tor 12th Jul 2019 9:20 pm

Re: Hacker GP42 and AL42 restoration help
 
Hi Frank connected speaker and plug for stylus and checked voltages again this is what i got compared to last readings

HT1 C12 286V
HT2 C11 272V
HT3 C8 248V
V1A PIN9 164V
V2A PIN9 120V
V1B PIN6 265V
V2B PIN6 265V
V1A PIN2 0V
V2A PIN2 0V
V1B PIN 7 7.1V
V2B PIN7 7.2V

dekor8tor 12th Jul 2019 10:10 pm

Re: Hacker GP42 and AL42 restoration help
 
Voltages G3 = 257v on both

Nuvistor 12th Jul 2019 10:14 pm

Re: Hacker GP42 and AL42 restoration help
 
Those look more like they should do, have you changed any components but I would have expected pin 2 to have about 1v on them. The Pentode cathodes are about right so the emission is ok.

dekor8tor 12th Jul 2019 10:17 pm

Re: Hacker GP42 and AL42 restoration help
 
No all i have done is connect the speaker

Nuvistor 12th Jul 2019 10:18 pm

Re: Hacker GP42 and AL42 restoration help
 
So the voltages you took before were without the speaker or dummy load?

dekor8tor 12th Jul 2019 10:19 pm

Re: Hacker GP42 and AL42 restoration help
 
Yes

Nuvistor 12th Jul 2019 10:21 pm

Re: Hacker GP42 and AL42 restoration help
 
Oh well you will know for the future, the amplifier was probably going unstable.

So back to the problem, check those components that Micheal suggested.

dekor8tor 12th Jul 2019 10:24 pm

Re: Hacker GP42 and AL42 restoration help
 
Ok thanks will do

'LIVEWIRE?' 14th Jul 2019 6:48 pm

Re: Hacker GP42 and AL42 restoration help
 
Incidentally a valve amplifier should never be run without either a loudspeaker or equivalent dummy load connected

dekor8tor 21st Jul 2019 10:12 pm

Re: Hacker GP42 and AL42 restoration help
 
Thanks for that livewire advice taken
Can anyone point me in the right direction for replacement rexine for the gondolier gp42 lid thanks

BRASSBITS 23rd Jul 2019 9:20 pm

Re: Hacker GP42 and AL42 restoration help
 
you wont get either of the 2 colours that Hacker used

dekor8tor 27th Jul 2019 9:51 pm

Re: Hacker GP42 and AL42 restoration help
 
ok thanks brassbits i did have a look and like you said i dont think i will get any
thanks for replying

leslie5555 28th Jul 2019 12:11 pm

Re: Hacker GP42 and AL42 restoration help
 
Hello can I ask why you want to replace the rexine on the lid, for example is it torn or frayed, or has it just discoulered/faded?

dekor8tor 2nd Aug 2019 10:09 pm

Re: Hacker GP42 and AL42 restoration help
 
Hi leslie i have a few woodworm holes in the lid
I have treated the casing with woodworm killer

Edward Huggins 3rd Aug 2019 8:58 am

Re: Hacker GP42 and AL42 restoration help
 
With patience these (pre-treated) holes can be filled. If you use a hard soap like Imperial Leather (which comes in 2 colour shades) slightly soften it in warm water and then just rub this over the affected area. Any surplus can be skimmed off using the edge of a Stanley knife blade. It will then harden. All this may sound a bit fastidious I know, but it really does improve the appearence.

dekor8tor 6th Aug 2019 9:59 pm

Re: Hacker GP42 and AL42 restoration help
 
Thank you Edward i will give that a go

dekor8tor 14th Aug 2019 5:07 pm

Re: Hacker GP42 and AL42 restoration help
 
Good afternoon everyone i just need a bit of advice on my 2 amps the one out of the gondolier and the one out of the al41
The amp in the gondolier has had the capacitors and resistors changed as advised by Michael Maurice and the other amp is untouched
The amp that has had the changes when all is connected back I have got a loud hum when the volume is turned up
Voltage across r6 is 78v and r7 is 113v on gp42
Voltage on untouched amp is r6 120v and r7 91v
Any help and advice will be greatly apprecciated thankyou

dekor8tor 14th Aug 2019 10:11 pm

Re: Hacker GP42 and AL42 restoration help
 
Hi all just anofher problem i put every thing back together plugged in the turntable and no power to turntable advice needed please


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