Standards Converter recommissioned. - UK Vintage Radio Repair and Restoration Discussion Forum

FERNSEH · 1st Sep 2022, 7:19 pm

I'm hoping to carry out tests on the vision and sound receivers in the Baird T5.
What better source of channel B1 signals for the set will be my own make standards converter. If it can be made to work again, that is.
The attachment shows the extensive use of TTL.

DFWB.

murphyv310 · 1st Sep 2022, 9:16 pm

Hi David.
Will be great to see the old chappie working again. You might need to wind it up on the handle though.

Pamphonica · 1st Sep 2022, 10:18 pm

Wonderful. I love TTL - who needs FPGAs?!
And the thick period dust will no doubt add a historically accurate "feel" to the picture.

Panrock · 2nd Sep 2022, 1:25 am

One of David's many achievements, and one which I think is particularly impressive.

Steve

murphyv310 · 2nd Sep 2022, 8:57 am

Hi
I concur with Steve, a very impressive achievement.
There is no way on this earth I could have done it.

FERNSEH · 2nd Sep 2022, 11:46 am

Many thanks for your kind comments.

Supplied with 625 line signals from a DVD player the correct 405 line sync pulse train is available from the baseband output and the modulator.
However, there is a fault or faults in the line stores.

DFWB.

FERNSEH · 2nd Sep 2022, 3:57 pm

Getting some results, fault might possibly be in the "Write Enable" (/WE) circuit in the primary line store board.

DFWB.

stevehertz · 2nd Sep 2022, 4:09 pm

I bought a 405 modulator of someone who was making them in the early 80s. It's in a large diecast box. Does anyone know who that may have been? I still have it and it's effectively surplus to requirements as I now have a Hedgehog SC.

Ed_Dinning · 2nd Sep 2022, 6:16 pm

I think there was a TELEVISION design, David Loser?

Ed

stevehertz · 2nd Sep 2022, 8:01 pm

Quote:

Originally Posted by Ed_Dinning

I think there was a TELEVISION design, David Loser?

Ed

Yes, David Loser. Is he 'around' these days?

Thanks Ed.

FERNSEH · 2nd Sep 2022, 8:40 pm

Found one fault which was causing the bad converted picture. The results are far from satisfactory but there is still a chance the converter can be restored to a reasonable standard.
A wire from one of the 74LS163 address counters had become disconnected from the line store IC.

DFWB.

FRANK.C · 3rd Sep 2022, 9:24 am

Hi David
What an incredible achievement.
The power supply looks substantial.
You have made great progress so far. It will be great to see it in action again.
I will be watching this thread with great interest.

Frank

FERNSEH · 3rd Sep 2022, 10:09 am

Hi Frank,
the last time the converter received any attention was in 2012.
It was found that certain modifications were possible to reduce the component count without degrading the performance.

DFWB.

FERNSEH · 3rd Sep 2022, 9:12 pm

Results of today's work. A problem was found in the write enable circuit, in fact it was a PCB artwork mistake.
Picture vertical stability could be better so that's something to attend to next week.
The camera captures only one picture field hence the prominent line structure.

DFWB.

FRANK.C · 3rd Sep 2022, 9:52 pm

That's brilliant David
It looks very good.

Frank

peter_scott · 4th Sep 2022, 9:15 am

I think the set is not doing justice to your converter.

Peter.

FERNSEH · 4th Sep 2022, 4:37 pm

Hi Frank,
definitely an improvement but the final results will never be as good as your excellent Hedghog converter or the Aurora.
Hi Peter,
As it stands now the Marconi VT161 isn't a very good set. However, because it was so reliable it was a popular rental set.
My set was made in 1958 and the serial number is... 1958!

DFWB.

Philips210 · 5th Sep 2022, 6:33 pm

That's a brilliant achievement designing and building a standards converter and great to see a TTL based circuit. It is a highly robust technology and fairly inexpensive to maintain, although some TTL ICs are becoming less easily available.

I built the Darius converter about 15 years ago and I'm pleased to get it all working which involved a great deal of work, but great fun all the same!
I'm currently building the Television magazine Test Card Generator May to July 1979 issues which uses 45 TTL ICs and a ZNA1034 SPG IC.

I'd love to be able to build David's standards converter if he would be happy share his circuit diagram.

Regards,
Symon

FERNSEH · 5th Sep 2022, 6:42 pm

Hi Symon,
my very first standards converter is still existence and is I'm informed still working well. It's a much simpler affair compared with the converter we're presently discussing, simply a 6bit line dropping converter, no interpolation. Assembled on verocards. Pictures are acceptable but there is a lot of missing vertical detail.
You're welcome to the circuit diagrams of both converters.

DFWB.

Philips210 · 5th Sep 2022, 6:53 pm

Thanks David, I appreciate that. I'll send you a PM later.

Regards,
Symon

1st Sep 2022, 7:19 pm	#1
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,459	Standards Converter recommissioned. I'm hoping to carry out tests on the vision and sound receivers in the Baird T5. What better source of channel B1 signals for the set will be my own make standards converter. If it can be made to work again, that is. The attachment shows the extensive use of TTL. DFWB. Attached Thumbnails

1st Sep 2022, 9:16 pm	#2
murphyv310 No Longer a Member Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,491	Re: Standards Converter recommissioned. Hi David. Will be great to see the old chappie working again. You might need to wind it up on the handle though.

1st Sep 2022, 10:18 pm	#3
Pamphonica Dekatron Join Date: Mar 2008 Location: Virginia Water, Surrey, UK. Posts: 3,186	Re: Standards Converter recommissioned. Wonderful. I love TTL - who needs FPGAs?! And the thick period dust will no doubt add a historically accurate "feel" to the picture. __________________ Jeremy, BVWS Chairman, BVWTM Friend, G8MLK, VMARS. www.pamphonic.co.uk www.bttt.org.uk

2nd Sep 2022, 1:25 am	#4
Panrock Nonode Join Date: Feb 2005 Location: Worcestershire, UK. Posts: 2,654	Re: Standards Converter recommissioned. One of David's many achievements, and one which I think is particularly impressive. Steve __________________ https://www.radiocraft.co.uk

2nd Sep 2022, 8:57 am	#5
murphyv310 No Longer a Member Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,491	Re: Standards Converter recommissioned. Hi I concur with Steve, a very impressive achievement. There is no way on this earth I could have done it.

2nd Sep 2022, 11:46 am	#6
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,459	Re: Standards Converter recommissioned. Many thanks for your kind comments. Supplied with 625 line signals from a DVD player the correct 405 line sync pulse train is available from the baseband output and the modulator. However, there is a fault or faults in the line stores. DFWB.

2nd Sep 2022, 3:57 pm	#7
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,459	Re: Standards Converter recommissioned. Getting some results, fault might possibly be in the "Write Enable" (/WE) circuit in the primary line store board. DFWB. Attached Thumbnails

2nd Sep 2022, 4:09 pm	#8
stevehertz Dekatron Join Date: Sep 2011 Location: Rugeley, Staffordshire, UK. Posts: 9,517	Re: Standards Converter recommissioned. I bought a 405 modulator of someone who was making them in the early 80s. It's in a large diecast box. Does anyone know who that may have been? I still have it and it's effectively surplus to requirements as I now have a Hedgehog SC. __________________ A digital radio is the latest thing, but a vintage wireless is forever..

2nd Sep 2022, 6:16 pm	#9
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,887	Re: Standards Converter recommissioned. I think there was a TELEVISION design, David Loser? Ed

2nd Sep 2022, 8:40 pm	#11
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,459	Re: Standards Converter recommissioned. Found one fault which was causing the bad converted picture. The results are far from satisfactory but there is still a chance the converter can be restored to a reasonable standard. A wire from one of the 74LS163 address counters had become disconnected from the line store IC. DFWB. Attached Thumbnails

3rd Sep 2022, 9:24 am	#12
FRANK.C Heptode Join Date: Feb 2006 Location: Roscommon, Ireland Posts: 760	Re: Standards Converter recommissioned. Hi David What an incredible achievement. The power supply looks substantial. You have made great progress so far. It will be great to see it in action again. I will be watching this thread with great interest. Frank __________________ www.electronics.frankcuffe.ovh

3rd Sep 2022, 10:09 am	#13
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,459	Re: Standards Converter recommissioned. Hi Frank, the last time the converter received any attention was in 2012. It was found that certain modifications were possible to reduce the component count without degrading the performance. DFWB.

3rd Sep 2022, 9:12 pm	#14
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,459	Re: Standards Converter recommissioned. Results of today's work. A problem was found in the write enable circuit, in fact it was a PCB artwork mistake. Picture vertical stability could be better so that's something to attend to next week. The camera captures only one picture field hence the prominent line structure. DFWB. Attached Thumbnails

3rd Sep 2022, 9:52 pm	#15
FRANK.C Heptode Join Date: Feb 2006 Location: Roscommon, Ireland Posts: 760	Re: Standards Converter recommissioned. That's brilliant David It looks very good. Frank __________________ www.electronics.frankcuffe.ovh

4th Sep 2022, 9:15 am	#16
peter_scott Dekatron Join Date: May 2003 Location: Edinburgh, UK. Posts: 3,289	Re: Standards Converter recommissioned. I think the set is not doing justice to your converter. Peter. __________________ http://www.nostalgiatech.co.uk https://www.youtube.com/c/PeterScott/videos

4th Sep 2022, 4:37 pm	#17
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,459	Re: Standards Converter recommissioned. Hi Frank, definitely an improvement but the final results will never be as good as your excellent Hedghog converter or the Aurora. Hi Peter, As it stands now the Marconi VT161 isn't a very good set. However, because it was so reliable it was a popular rental set. My set was made in 1958 and the serial number is... 1958! DFWB.

5th Sep 2022, 6:33 pm	#18
Philips210 Nonode Join Date: May 2007 Location: Redruth, Cornwall, UK. Posts: 2,683	Re: Standards Converter recommissioned. That's a brilliant achievement designing and building a standards converter and great to see a TTL based circuit. It is a highly robust technology and fairly inexpensive to maintain, although some TTL ICs are becoming less easily available. I built the Darius converter about 15 years ago and I'm pleased to get it all working which involved a great deal of work, but great fun all the same! I'm currently building the Television magazine Test Card Generator May to July 1979 issues which uses 45 TTL ICs and a ZNA1034 SPG IC. I'd love to be able to build David's standards converter if he would be happy share his circuit diagram. Regards, Symon

5th Sep 2022, 6:42 pm	#19
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,459	Re: Standards Converter recommissioned. Hi Symon, my very first standards converter is still existence and is I'm informed still working well. It's a much simpler affair compared with the converter we're presently discussing, simply a 6bit line dropping converter, no interpolation. Assembled on verocards. Pictures are acceptable but there is a lot of missing vertical detail. You're welcome to the circuit diagrams of both converters. DFWB.

5th Sep 2022, 6:53 pm	#20
Philips210 Nonode Join Date: May 2007 Location: Redruth, Cornwall, UK. Posts: 2,683	Re: Standards Converter recommissioned. Thanks David, I appreciate that. I'll send you a PM later. Regards, Symon