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Return to top of page · Post #: 1 · Written at 9:25:33 AM on 14 July 2009.
	Nzbhoy Location: Kaiapoi, NZ Member since 20 December 2008 Member #: 399 Postcount: 30
I recently came across this radio which has "licensed by Radio Corporation of America" on the chassis also the number 35A5764 stamped on the back chassis also 10/5/35 scratched on the chassis It has Air Raider seven valve all wave printed on the dail I can not seem to find any info on this any where would any one be able to help as it made ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾ Nzbhoy

Return to top of page · Post #: 2 · Written at 10:41:43 PM on 14 July 2009.
	Marcc Location: Wangaratta, VIC Member since 21 February 2009 Member #: 438 Postcount: 5389
Not unreasonable to assume that it is a RCA circuit that is known. We need to know the valve compliment to have any idea of where to start. Marc

Return to top of page · Post #: 3 · Written at 11:14:27 AM on 15 July 2009.
	Nzbhoy Location: Kaiapoi, NZ Member since 20 December 2008 Member #: 399 Postcount: 30
Hi Marc the line up is 80, A5, 55,58,58,57, ? unfortunatly the last one has nothing on it any help would be great thanks Alec ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾ Nzbhoy

Return to top of page · Post #: 4 · Written at 1:11:57 PM on 15 July 2009.
	Marcc Location: Wangaratta, VIC Member since 21 February 2009 Member #: 438 Postcount: 5389
A5 sounds like a 2A5 See if that is physically identical to the unknown? It could be in Push Pull with another the same? Breath on the glass sometimes the moist breath on a cold valve will show the number Marc

Return to top of page · Post #: 5 · Written at 1:44:35 PM on 15 July 2009.
	Marcc Location: Wangaratta, VIC Member since 21 February 2009 Member #: 438 Postcount: 5389
OK Set is consistent with 1935 and is a fairly standard autodyne configuration This follows a similar patern to a Healing 53E and one I have yet to identify but reverse engineered,in order to get it going. The unidentified valve is likely to be a 58 and the set will have a 3 gang tuner. How I think it will all pan out -- 58 1st RF amp Pentode 57 Oscillator Mixer Pentode 58 2nd RF amp Pentode 55 Double diode triode detector & first AF amp 2A5 Audio Power Amp Pentode 80 Rectifier Double diode Full wave Rectifier You will not find it in AORSM's it's too early. One can still muddle through & fix it needs be, without a circuit. I will see what other info I can glean?

Return to top of page · Post #: 6 · Written at 8:10:34 PM on 15 July 2009.
	Nzbhoy Location: Kaiapoi, NZ Member since 20 December 2008 Member #: 399 Postcount: 30
You are right its 2A5 not A5 the unidentified valve is not a 58. it has 5 pins and sits alone Many thanks for your help Marc ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾ Nzbhoy

Return to top of page · Post #: 7 · Written at 11:29:22 PM on 15 July 2009.
	Marcc Location: Wangaratta, VIC Member since 21 February 2009 Member #: 438 Postcount: 5389
Did you suffer any damage in the Earthquake? The isolated valve may be sitting on a load of coils? This would make it similar to the Healing 53. If this is so, it may well be a 56 (76) Triode used as a seperate oscillator, this to supply sufficient drive, as its Shortwave (I would surmise).

Return to top of page · Post #: 8 · Written at 12:27:32 PM on 16 July 2009.
	Nzbhoy Location: Kaiapoi, NZ Member since 20 December 2008 Member #: 399 Postcount: 30
I never even felt the earthquake supposed to be more on the way media make a big song and dance about it After brushing out all the mouse droppings and dirt and cobwebs I powered up the radio slowly yesterday and after some funny squeaks and Squeals it came to life and to my amazement it was loud and clear even though all of the capacitators looked totally ruined (leaking, one is so bad I cant believe it still does the job) and need to be replaced (who needs modern technology) so I will slowly bring this up to scratch I still would like to know the unknown valve number it is not a 76 as you suggested as I tried one in without any joy I have also asked Brad to put a pic on of the back of this radio it may help ? many thanks again Marc Alec ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾ Nzbhoy

Return to top of page · Post #: 9 · Written at 12:29:08 PM on 16 July 2009.
	Nzbhoy Location: Kaiapoi, NZ Member since 20 December 2008 Member #: 399 Postcount: 30
Oh and you were right , ts a 2A5 not A5 cheers ‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾ Nzbhoy

Return to top of page · Post #: 10 · Written at 10:00:33 PM on 16 July 2009.
	Marcc Location: Wangaratta, VIC Member since 21 February 2009 Member #: 438 Postcount: 5389
May have worded that wrong. 76 is the preferred replacment for 56. I would be surprised if its a 76 albeit that they are pin interchangeable. The fact that it works is good although I would expect the electrolytics (if any) too have dried out, or if it has "wet type" cans, for them to leak physically. Isolate these from circuit, do not be tempted to parallel them with new ones. The papers may not be leaking furiously. I did fire up a Lyric 70 Series, with the original caps in it, knowing full well that some were leaking badly and in the face of it having 375V DC on the 50 output valve. Some of those like the Lyric and Healing had 2 & 3μF Non polarised caps. To avoid using parallel Mains MKT to get this at high voltages. Do consider motor start types. Most will not punch through below 1500VDC. Have fun with it ... enjoy it. Marc

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