Sharp TRP801
 

I recently acquired this Sharp transistor TV set.
This 1960 set was designed to operate on the 819 line standard in France. I don't think a version for the UK was ever made.

My set has a UHF conversion unit so the set must work OK on the 625 line standard system L.
For system I a FM sound stage will have to installed and the vision demodulator changed for negative vision modulation systems.

The set has real early sixties look about it.

For the time being the will be a display item.

DFWB.

Re: Sharp TRP801.
 

Wow! I didn't think Sharp were around back then, Sony yes but not Sharp.
What a great find!

Cheers,
Brian

Re: Sharp TRP801.
 

Hi Brian,
Actually, Sharp is a very old firm, starting their business in 1915 making the EverSharp propelling pencil. I don't know when they diversed into electronic items.
I believe Sharp made their first production TV set in 1953.
As for sales in the UK, Sharp (UK) Ltd. started trading in 1973/4. Before that date their products must have been imported by private concerns.

Returning to the TRP801. Versions will have been made for the NTSC countries. It is likely that it was uneconomical to make a 405 line set.

DFWB.

Sharp TRP801 revisted.
 

I introduced this interesting portable 819 line TV set in this forum in 2006.
It's about time I made a start on the restoration.
The receiver is equipped with an UHF tuner for 625 line system L transmissions.

DFWB.

Re: Sharp TRP801
 

The add-on UHF tuner. Note the mixer diode. No RF amplifier. Typical late fifties and early sixties practise.

DFWB.

Re: Sharp TRP801
 

Hi David,
I'm glad I'm not the only one that takes a long time to get round to things!!

That PCB looks very well made. Is it double sided or did they just choose to mount the components on the print side? It's very neatly drawn as well- almost like it's been done with CAD software rather than drawn by hand.

Most early PCB's have very curly tracks- it's hard to believe it dates from 1960!

Are those Toshiba logo's I can see on the transistors?

I wonder how good those wax covered caps will be? Or will they have suffered as badly as our British ones?

Looks like another interesting restoration is on the cards!

All the best
Nick

Re: Sharp TRP801
 

Hi Nick,
It's a single sided printed circuit board and the print layout shown on the components side is a most welcome if any serious servicing is required.
There is a mixture of Toshiba and Hitachi transistors, also some Sharp branded power types. The CRT was made for Sharp by the Hayakawa Electric Co. Ltd., type 210EB4.

DFWB.

Re: Sharp TRP801
 

Hi to all,

An advert for the Sharp TRP-801 by the French importer (General Television)

+ a reduced weight schematic.

Fernseh already has the full data,

Best Regards
jhalphen

Re: Sharp TRP801
 

Hi Jerome,
many thanks for sending me the servicing information, now I have no excuses but to just get on with the restoration of this interesting receiver.
Noteworthy is the six stage vision IF amplifier, the circuit designer had real gain versus bandwidth considerations for the 819 line system.
Systems E and L employed positive video modulation so that helped to simplify things somewhat. AM sound.

DFWB.

Re: Sharp TRP801
 

Hello David, What an interesting set there. I enjoy reading about these early 60s portables although I have never repaired one. Looking at the circuit diagram I can't help noticing the 2 valves in the EHT doubler don't appear to have any heater supply from the LOPT. Am I missing something here? Look forward to reading more.

Alan.

Re: Sharp TRP801
 

Hi Alan,
according to the information for the 5642 HV rectifiers the valves have directly heated cathodes. The line output transformer will have separate highly insulated windings for each valve. The filament voltage is only 1.25V so it's possible only one turn is all that's required on the transformer.

From the Radiomuseum: https://www.radiomuseum.org/tubes/tube_5642.html

From R-type.org: http://www.r-type.org/exhib/aai0016.htm

DFWB.

Re: Sharp TRP801
 

It's a splendid looking set, and matches the red shoes splendidly.

Can't see any standards switching. Is 625 simply in range of the line hold?

I'd probably be ditching that UHF tuner, assuming the VHF one is still there.

Re: Sharp TRP801
 

That's interesting - and a nicely drawn diagram too. Is the PCB blank on the reverse side? I notice there are supplies fed from the LOPT which must have been a relatively new concept at the time, and would have needed fast switching diodes..

Re: Sharp TRP801
 

Hayakawa Tokuji was the founder of Sharp, so chances are Hayakawa Electric would have been a fully owned subsidiary.

Re: Sharp TRP801
 

From Wikipedia:
https://en.wikipedia.org/wiki/Tokuji_Hayakawa

DFWB.

Re: Sharp TRP801
 

Sharp got around e.g. Three Aces Electronics - Part Hardcourt .... Nigeria.

Re: Sharp TRP801
 

That's "Port" .... !!!

Re: Sharp TRP801
 

News Flash! The line oscillator is functioning on both standards.

The CRT and line output transistor removed in order to carry out initial tests.
Power supplier set to 12volts and connected to the full-wave rectifier diodes. Oscilloscope connected to the base wire of the line output transistor. The attachments show the base drive waveforms on 625 and 819 lines.
The frame oscillator is working but there is no waveform present at the collector of the output transistor.

DFWB.

Re: Sharp TRP801
 

Hello to all,

@Fernseh : Great ! David, nice progress.

Do you have an Aurora with 819 RF out to test the receiver in VHF E standard ?

Maybe you have a 819 capable generator from your several visits to France.

Best Regards
jhalphen
Paris/France

Re: Sharp TRP801
 

"Do you have an Aurora with 819 RF out to test the receiver in VHF E standard" ?
Hi Jerome,
I still have the original multi-standard Aurora converter, this device doesn't have a modulator and for 819 lines I use the System E modulator that Wilfrid made for me. Outputs to channel F8
Also for 819 lines the Philips GM2891 pattern generator donated to me by Mr. Poulain. It's the /13 version. Similar instruments were made for USA standard M (/60)and CCIR 625 lines (/50). Never seen a 405 line version.
Instrument uses an early UHF valve, the EC80:
https://www.radiomuseum.org/tubes/tube_ec80.html

DFWB.