Marconi 702 going up for auction (News story)...

[VintagePC]

Thought this might be of interest to the folks here:

http://www.telegraph.co.uk/news/ukne...-for-5000.html

[David Roper]

Stunning ignorance of early British TV history on display in the accompanying article.

[stromberg6]

Originally Posted by David Roper

Stunning ignorance of early British TV history on display in the accompanying article.

Yes, and everybody on this side of the pond knows that RCA invented TV, and broadcast the first program, right? LMAO!!
Kevin

[jeyurkon]

Here's a chronicled restoration of one.

http://www.radiocraft.co.uk/702.htm

For the uniformed like myself, perhaps someone could point out the errors in the Telegraph article.

[electroking]

Originally Posted by jeyurkon

Here's a chronicled restoration of one.

http://www.radiocraft.co.uk/702.htm

For the uniformed like myself, perhaps someone could point out the errors in the Telegraph article.

I may be wrong, but I believe it's the same set that is being sold.

P.S.: link above ends with a note that the TV was sold at
auction in September, 2010, so maybe it is being sold again...

[VintagePC]

That restoration is a good read; clearly someone who does it for the joy and challenge, as well as wanting to preserve!

[Dave A]

Or it could be this one;

http://news.bbc.co.uk/2/hi/technology/8159406.stm

Or they may all be the same set but the one up for auction shows a quite strong CRT.

[ppppenguin]

I've seen the set that's being offered for sale. It is neither my set nor Steve Ostler's set as suggested below. It has been discussed extensively here: http://www.vintage-radio.net/forum/s...t=65666&page=2 The press reports are unfortunate. AFAIK one journalist took a few facts and made some erroneous deductions. The others all copied. Here is my report on the set, as posted in the UKVRR thread linked above:

This is a most interesting set. I had a close look at it this morning and we took out the escutcheon with the system switch for closer examination. The switch itself is not original and is not connected. There is also a clear outline of where the blanking plate was fitted. It is possible that the blanking plate is in the boxes of bits that are with the set.

It is clear that at some point the original 405/50 and 240/25 were ground out and new ones engraved. The 2 from 240 is easily visible and part of the 5 from 25 can be seen. I suggested a theory that the set had been made with the switch the wrong way round and rather than dismantle the set to rectify the problem the escutcheon was simply re-engraved. It was only after this that Laurence told me that the user manual for the set has a typewritten note pasted over the original instructions for the system switch. QED. There may be other sets like this.

The CRT is one of the brightest prewar EMI 12" ones I have seen. I would dearly love to have such a good CRT in my own set. From fallible memory it's brighter than the one in Russell's set too.

Another anomaly is the single mains switch. My set has 2 switches, one for mains, the other for vision though the latter is not connected on my set (s/n H1132). There is no evidence that a 2nd switch was ever fitted to the set at Bonhams.

The EHT smooting cap has been replaced by a more modern component. the old part is in the box of bits. Also in the box of bits are a couple of rather impressive looking ESU101 mercury vapour rectifiers. http://www.shinjo.info/frank/sheets/147/e/ESU101.pdf plus an alternative EHT transformer. A KitKat tin contains a VHF modulator with PSU, looks like the David Looser design.

The set is generally working but could do with a general electronic overhaul. Several controls are right up one end, focus is on its endstop and still not too good. Overall, a lovely set.

[kx250rider]

Now it's obvious where Sarnoff stole the design for the TRK-12.

Charles

[tubesrule]

Originally Posted by kx250rider

Now it's obvious where Sarnoff stole the design for the TRK-12.

Charles

I don't think anything for the TRK-12 was borrowed from this design. The TRK-12 was based off the RR359B. The later ones were already using such things as the 12AP4, cardboard crt protector and rubber mask that ended up on the TRK-12.

Now the first Dumonts were exact copies of the British Cossor designs.

Darryl

[Steve McVoy]

No similarity in the electronic design of the Marconi 702 and the RCA TRK-12, and the cabinet was designed by John Vassos. So I don't think anything was copied from Marconi.

Though the British were the first to broadcast regular "high definition" programming (because of the government-owned BBC) RCA developed the technology and the British basically copied it. There was some licensing agreement between RCA and EMI that allowed them to use the iconoscope design, which became the Emiscope in Britain.

[ppppenguin]

Originally Posted by Steve McVoy

Though the British were the first to broadcast regular "high definition" programming (because of the government-owned BBC) RCA developed the technology and the British basically copied it. There was some licensing agreement between RCA and EMI that allowed them to use the iconoscope design, which became the Emiscope in Britain.

That's all a bit contentious. Yes, there was a patent share between RCA and Marconi (not EMI) which may well have been a reason why Marconi and EMI formed M-EMI to develop TV in the UK. One of the most important patents was Ballard's on interlace though there was plenty of prior art on interlace (intercalation) going right back to Baird.

It is a common misconception that government owns or owned the BBC. The BBC exisits in a curious arrangement which isn't a commercial company but isn't owned by the gvernment.

The relationship between the Iconoscope and Emitron (not Emiscope) is controversial. I understand that further research is going on in this field which will shed new light on the RCA/M-EMI relationship as well as much else in that period of television.

[Steve McVoy]

Thanks for pointing out the errors in my post. I look forward to finding out the details of the RCA/M-EMI relationship.

[kx250rider]

I know it's juvenile, but I want to pin any tech theft on Sarnoff, as he got away with so much of it.

Charles

[tubesrule]

Well, it just sold today for £16800 ($27.5K). Supposedly went to a buyer outside the UK.

Darryl