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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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16th May 2018, 12:03 pm | #1 |
Hexode
Join Date: Jan 2018
Location: Portsmouth, Hampshire, UK.
Posts: 421
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Broken valve........
I wonder if anyone may be able to identify this valve?
It was a victim of the dread courier despite my best efforts in advising the sender to remove the valves & pack them separately (which they did most adequately), they could not have foreseen the devious machinations of said courier. Any help would be most gratefully received, I've looked through the valve museum's collection of Osram valves until I nearly went square eyed. Many thanks in advance.
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16th May 2018, 12:12 pm | #2 |
Moderator
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Location: Ipswich, Suffolk, IP4, UK.
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Re: Broken valve........
What set did it come from? What other valves were fitted?
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16th May 2018, 12:29 pm | #3 |
Hexode
Join Date: Jan 2018
Location: Portsmouth, Hampshire, UK.
Posts: 421
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Re: Broken valve........
Well, that's part of the problem, the set is believed to be a Graves but, as with most of Graves radios, there is little to no information about it. All I am able to say is the set is a three valve battery with speaker output. The markings on one of the valves appears to be H210 by Osram (cross referenced against the valve museum & it checks out), the other valve has no legible markings other than the Osram label. As far as I can see there are no labels etc. on the inside of the cabinet or chassis. The photo is from a Google search and is simply to give a general idea of the appearance. According to the website this set appears on it is a Graves Minerva but that's the only reference I can find after many hours of searching. I've attempted to contact the site owner to no avail.
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The difference between stupidity and genius is that genius has its limits. (Einstein) |
16th May 2018, 12:37 pm | #4 |
Hexode
Join Date: Jan 2018
Location: Portsmouth, Hampshire, UK.
Posts: 421
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Re: Broken valve........
Shot of the inside of the cabinet.
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The difference between stupidity and genius is that genius has its limits. (Einstein) |
16th May 2018, 1:10 pm | #5 |
Dekatron
Join Date: Sep 2005
Location: Seaford, East Sussex, UK.
Posts: 5,997
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Re: Broken valve........
It was an Osram P2. (probably)
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16th May 2018, 1:13 pm | #6 |
Nonode
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 2,196
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Re: Broken valve........
What a disappointment! Nice interesting looking radio too.
It shouldn't be too difficult to find a replacement for the broken valve. As you know it's a battery set, and the valve has got just 4 pins and no sign of an additional terminal on the side or top, it's a triode with a 2-volt heater. my impression from occasionally playing with vintage battery sets is that back in those days, battery triodes were pretty well interchangeble, perhaps with some adjustment of grid bias. Your broken specimen may well not have been original anyway. I'd try and get hold of a PM2, HL2, HL210 or listed equivalents whatever you can find at an affordable price. Best of luck! Martin
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16th May 2018, 2:14 pm | #7 |
Octode
Join Date: Jul 2008
Location: Gloucestershire, UK.
Posts: 1,043
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Re: Broken valve........
Hello,
The size of the anode suggests an output valve and it is Marconi-Osram which suggests a P2 or LP2. http://r-type.org/exhib/aby0053.htm http://r-type.org/exhib/aaq0093.htm Yours, Richard |
16th May 2018, 2:48 pm | #8 |
Hexode
Join Date: Jan 2018
Location: Portsmouth, Hampshire, UK.
Posts: 421
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Re: Broken valve........
A most excellent result gentlemen!
I will be, no doubt, posting more pictures/queries as this story unfolds. Many, many thanks to all, very much appreciated.
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The difference between stupidity and genius is that genius has its limits. (Einstein) |
17th May 2018, 1:46 pm | #9 |
Hexode
Join Date: Jan 2018
Location: Portsmouth, Hampshire, UK.
Posts: 421
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Re: Broken valve........
As a bit of an update:
Having had a quick look over the radio last night it would appear that it has been "restored" at an earlier time, the chassis has been painted but there is evidence of corrosion below the paint ie pitting etc. The three controls on the front are: far right: tuning (variable capacitor), middle (long/off/medium) & far left what would appear to be volume. I'll take the chassis out tonight & take some photos to post. Hopefully it'll help unfold this mystery set a little...
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19th May 2018, 11:55 am | #10 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
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Re: Broken valve........
A three-valve battery set of that vintage is probably regenerative, so your 'volume' control may actually be a regeneration control.
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20th May 2018, 1:38 pm | #11 |
Hexode
Join Date: Jan 2018
Location: Portsmouth, Hampshire, UK.
Posts: 421
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Re: Broken valve........
G6Tanuki, you are indeed correct, once I'd got the chassis out of its case I found it was another variable capacitor so regenerative it is.
I've taken some more photos & Ormond seems to be cropping up on just about every part! I've done some research regarding them & there isn't a great deal of information, possibly a re-cased chassis? Then again, I have seen a couple of these cases on the internet & they are reputedly from J. G. Graves? The plot thickens!
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The difference between stupidity and genius is that genius has its limits. (Einstein) |
20th May 2018, 2:16 pm | #12 |
Dekatron
Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,941
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Re: Broken valve........
That large (aerial?) matching transformer is a thing of beauty in itself. Several wave wound sections and the single layer.
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