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 Info Wanted About This Audio Signal Generator
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 Return to top of page · Post #: 1 · Written at 11:12:42 AM on 26 October 2019.
Cpsmusic's Gravatar
 Location: Melbourne, VIC
 Member since 18 February 2014
 Member #: 1507
 Postcount: 51

Hi Folks.

I'd like to find out some information (hopefully a schematic) about this audio signal generator. It was built by my late-father probably in the '50s and is most likely based on an article in one of the Australian electronics magazines like R&H, RT&H or Wireless World (?). I'd like to get the unit working however it needs an external power supply which seems to have gone missing.

Anyone recognise it or the article that it is based on?

https://photos.app.goo.gl/N4QaWdbMFgzUH36w5

Cheers,

Chris


 
 Return to top of page · Post #: 2 · Written at 7:00:00 PM on 26 October 2019.
Fred Lever's Gravatar
 Location: Toongabbie, NSW
 Member since 19 November 2015
 Member #: 1828
 Postcount: 563

A very nicely made piece of equipment!
I only found 2 photos in the link, are there more showing the valve line up and top side parts?
Fred.


 
 Return to top of page · Post #: 3 · Written at 7:54:33 PM on 26 October 2019.
Cpsmusic's Gravatar
 Location: Melbourne, VIC
 Member since 18 February 2014
 Member #: 1507
 Postcount: 51

I'll add them.


 
 Return to top of page · Post #: 4 · Written at 7:54:47 PM on 26 October 2019.
Cpsmusic's Gravatar
 Location: Melbourne, VIC
 Member since 18 February 2014
 Member #: 1507
 Postcount: 51

I'll add them.


 
 Return to top of page · Post #: 5 · Written at 7:59:28 PM on 26 October 2019.
Cpsmusic's Gravatar
 Location: Melbourne, VIC
 Member since 18 February 2014
 Member #: 1507
 Postcount: 51

From Left to Right the valves are:

7N7 6V6 6SN7 6AG5 (x2)


 
 Return to top of page · Post #: 6 · Written at 8:07:36 PM on 26 October 2019.
Cpsmusic's Gravatar
 Location: Melbourne, VIC
 Member since 18 February 2014
 Member #: 1507
 Postcount: 51

I've added a picture of the top to the album at the link above.


 
 Return to top of page · Post #: 7 · Written at 1:01:01 AM on 27 October 2019.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 3685

That may be a reverse engineer job. Bit odd 7N7 and 6SN7 One is a loctal the other an octal but its the same? 6AG5 is the weird one as it has two cathode pins 2 & 7 and is a Pentode often wired Triode (Screen tied to Plate).

There are several capacitors that will need replacing & I suspect that a couple are replacements

Marc


 
 Return to top of page · Post #: 8 · Written at 2:18:15 PM on 28 October 2019.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 3685

Fred don't consider an apology needed. You will note its got rubber sheet between base & the rails: Often where there is vibration & shock loading plus concrete, there has to be some sort of shock absorber. I some times wonder if the railways have worked that out?

As noted both Lathe & Press are 1982 Fuse Box 2016. Press has already chewed up a set of belts & to replace the belts in the lathe with the same type, the spindle has to come out for starters.


 
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