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 Help in identifying a Chassis make and model
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 Return to top of page · Post #: 31 · Written at 1:19:28 PM on 19 January 2017.
Scotty's Gravatar
 Location: Melbourne, VIC
 Member since 26 December 2010
 Member #: 794
 Postcount: 328

Hi again,
Does anyone have the schematic for the President Tasma M51? We have restored the audio output side which is now working fine with a 6M5 installed. But the radio side is not working at all.


 
 Return to top of page · Post #: 32 · Written at 2:48:49 PM on 19 January 2017.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4545

51 does not have the same chassis layout & the plugs are on the rear panel. albeit the circuit may be similar.

Did you make any attempt to replace the paper caps & electrolytic caps, before you turned it on? Great way of burning out a transformer.

I will have circuit for 51 and the others. One dodgy wax paper will be enough to kill it. As I have said many times, fault finding whilst those caps are still in there is non productive and risks damage. The time is better spent replacing them. 90% of the time, they are the problem.

Marc


 
 Return to top of page · Post #: 33 · Written at 3:58:03 PM on 19 January 2017.
Gandhn's Gravatar
 Location: Cameron Park, NSW
 Member since 5 November 2010
 Member #: 770
 Postcount: 352

Here is the circuit of the President Tasma M51.
Harold

President Tasma M51 Circuit Diagram


 
 Return to top of page · Post #: 34 · Written at 4:11:02 PM on 19 January 2017.
Scotty's Gravatar
 Location: Melbourne, VIC
 Member since 26 December 2010
 Member #: 794
 Postcount: 328

Yes caps have been changed


 
 Return to top of page · Post #: 35 · Written at 9:01:21 PM on 19 January 2017.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4545

Good move, these things run on smoke & we do not want it to escape: They rarely work if it does.


 
 Return to top of page · Post #: 36 · Written at 10:02:52 PM on 19 January 2017.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 6625

Document uploaded to Post 33.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 37 · Written at 10:56:10 AM on 21 January 2017.
MonochromeTV's avatar
 Location: Melbourne, VIC
 Member since 20 September 2011
 Member #: 1009
 Postcount: 1136

The chassis is a A.W. Jackson Precedent, not a President Tasma.

The only thing that throws is me is the 9-pin (6AN7?) converter valve. All 5 valve Precedents I've seen use a 6BE6 pentagrid for a converter. But then it is not unknown that some outfits chop & change. Also we don't know if it is a broadcast (AM) only, or broadcast and short-wave.

Marcc mentioned a possible valve socket just peeking behind the first I.F. can, which would make it a 6 valver. If this is the case then it could be a Precedent M615.


 
 Return to top of page · Post #: 38 · Written at 2:57:21 PM on 21 January 2017.
Gandhn's Gravatar
 Location: Cameron Park, NSW
 Member since 5 November 2010
 Member #: 770
 Postcount: 352

I cannot see a valve socket near the first IFT, looking at a hi res under chassis photo. Two sets of aerial and oscillator coils makes it a dual wave and using a 2 gang tuning cap means there is no RF stage.

Other Precedent models in AORSM don't fit, 534DW uses an octal 6SA7 mixer and the 534A uses a 6BE6 7 pin mixer. Having said that, these circuits and the Tasma President models referred to earlier are all very similar, so I don't think we have pinned down the exact model yet.

Harold


 
 Return to top of page · Post #: 39 · Written at 11:17:09 PM on 21 January 2017.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 4545

Basically in noting the similar valve line up & speaker socket used, it is a worthwhile exercise to follow the circuit/s I noted through and see if it actually matches, noting where it doesn't, if you have that scenario.

I never find it unusual to find oddball things, in sets that have been got at.

Marc


 
 Return to top of page · Post #: 40 · Written at 5:07:25 PM on 24 January 2017.
Scotty's Gravatar
 Location: Melbourne, VIC
 Member since 26 December 2010
 Member #: 794
 Postcount: 328

Hi all,
Monochrome asked if the unit was AM and SW - yes it is.
Cheers


 
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