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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
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8th Nov 2018, 12:41 am | #21 | |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,711
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Re: Bush A774
Quote:
I snapped that sign in the mild climate of Gibraltar, and thought it might date back further than the 70s
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8th Nov 2018, 1:15 am | #22 |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,711
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Re: Bush A774
I don't recall replacing many LOPTXs in RBM 774's. What I do remember is the DY86 heater single-turn winding arching to the loptx core, and having to rewire it with a loop of EHT cable. Quite a satisfying job in the customers lounge.
And don't forget a bit of preventative maintenance like the soldered joints on that earthing bar that ran round the chassis, and could cause intermittent hum bars. A Weller gun was good for that job.
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8th Nov 2018, 2:11 am | #23 | |
Heptode
Join Date: Aug 2009
Location: High Wycombe, Bucks. UK.
Posts: 811
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Re: Bush A774
Quote:
I do have a couple of A774's in my collection. One came from Neil29 last year. I got it working - see this thread https://www.vintage-radio.net/forum/...d.php?t=138858 Main faults were a leaky capacitor in the frame stage and broken plastic parts in the tuner mechanism. Heatercathodeshort kindly sent me some spare parts, and earlier this year, gave me another A774 set, a 20" Murphy in a white cabinet which isn't in great condition. Also the CRT is marked. I haven't restored this one yet. I'm a bit nostalgic about these A774 sets. Back in the late 1970s my parents rented a Murphy A774 from Hooper and Son in Brislington, Bristol. It was fairly unreliable even then, rarely lasting more than 3 months before needing repair. Sometimes we were loaned another TV while it was away being repaired. A couple of times we got a Ferguson BRC 1500 with the piano-key tuner. Despite the 1500's reputation for poor picture quality, it seemed better than the A774 to me. Finally in late 1979 the Murphy A774 went bang just as "Top of the Pops" was about to start. I was very annoyed that I missed the show, but every cloud has a silver lining. Hoopers took away the dead Murphy A774 for repair and loaned us a Philips G11 colour TV instead. We were so impressed that we asked if we could keep it. A deal was done with the shop and the Philips G11 was ours. I expect the shop rejoiced and deposited the old A774 in the nearest dustbin. The G11 proved much more reliable, averaging 1 failure every 2 years. |
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8th Nov 2018, 1:11 pm | #24 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
Posts: 6,916
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Re: Bush A774
A classic 'we don't have a black and white TV but here's a colour one' sales pitch! You just wouldn't go back and they knew that.
I only saw a few A774s although A640s were regular visitors - in fact I think I saw more A816s. I thought they looked nice and easy to service, which I suppose they were. That's the 774 - the 816 was another story, but mainly LOPT based as well. |
8th Nov 2018, 2:06 pm | #25 | |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,711
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Re: Bush A774
Quote:
I'm sure we did do that, but whilst not wanting to divert the thread too far towards TV licencing politics, how did we manage that without turning our customers into criminals?
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9th Nov 2018, 3:30 am | #26 |
Pentode
Join Date: Nov 2017
Location: Birmingham, West Midlands, UK.
Posts: 171
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Re: Bush A774
Back in 1971 as a trainee at Currys one of my jobs was parcelling up and sending back faulty parts under gurantee. In the first 6 months in the job I remember sending back 3 or 4 A774 LOPTs to RBMs service department at Boreham Wood, all from brand new sets just put out on display. Some had failed within a few days of operation, so heaven knows how many had packed up after sale as these would have been dealt with in the field. The 2 models they sold were TV191s 20 inch and TV193s 24inch. To be fair to RBM replacements arrived within a few days. Happy days.
Alan Last edited by AJSmith625; 9th Nov 2018 at 3:35 am. Reason: additional text added. |
9th Nov 2018, 10:40 am | #27 |
Nonode
Join Date: Jan 2004
Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area.
Posts: 2,965
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Re: Bush A774
I don't know what happened at RRI but something major did from producing one of the best dual standard TV's ever with the A640 to the disastrous A774 was a big retro step. We found the A774 was heavy on tubes and LOPT's, PCL805,s suffered a high mortality rate due to being placed just above the mains dropper, on off switch failures, very difficult to cure background hum on the sound even after RRI bought out various mods to overcome this.
Then there was the fault of intermittent poor sync, line tearing and hum bars which meant tipping the set on its front set to resolder all those chassis lugs on the main PCB, an official mod came out to link all these lugs with wire links. Some of the last A774 sets already had this done. I still have somewhere a bag of those blue replacement tuner slugs, which was also a problem on the A823 colour sets which used the same mechanical tuner. We did so many of these tuner repairs I can still probably do this job in my sleep. Once you had overcome these problems and with careful set up the A774 could produce a fair and reasonably stable picture but even at best was not a patch on other black and white sets of this era including the earlier RBM A640 and the 625 single standard black and white sets from Decca, GEC, ITT and Pye.
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