Tech Talk

Forum home - Go back to Tech talk

Help in identifying a Chassis make and model
« Back · 1 · 2 · 3 · Next »
Return to top of page · Post #: 31 · Written at 1:19:28 PM on 19 January 2017.
	Scotty Location: Melbourne, VIC Member since 26 December 2010 Member #: 794 Postcount: 387
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 Location: Wangaratta, VIC Member since 21 February 2009 Member #: 438 Postcount: 5254
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 Location: Cameron Park, NSW Member since 5 November 2010 Member #: 770 Postcount: 388
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 Location: Melbourne, VIC Member since 26 December 2010 Member #: 794 Postcount: 387
Yes caps have been changed

Return to top of page · Post #: 35 · Written at 9:01:21 PM on 19 January 2017.
	Marcc Location: Wangaratta, VIC Member since 21 February 2009 Member #: 438 Postcount: 5254
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 Administrator Location: Naremburn, NSW Member since 15 November 2005 Member #: 1 Postcount: 7301
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 Location: Melbourne, VIC Member since 20 September 2011 Member #: 1009 Postcount: 1182
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 Location: Cameron Park, NSW Member since 5 November 2010 Member #: 770 Postcount: 388
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 Location: Wangaratta, VIC Member since 21 February 2009 Member #: 438 Postcount: 5254
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 Location: Melbourne, VIC Member since 26 December 2010 Member #: 794 Postcount: 387
Hi all, Monochrome asked if the unit was AM and SW - yes it is. Cheers

« Back · 1 · 2 · 3 · Next »
You need to be a member to post comments on this forum.

Tech Talk

Sign In