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Title: Any idea what tube these are? Post by: N0WEK on April 02, 2014, 12:04:56 AM I got these some time ago in a big assortment of tubes. The only identifying marks are:
SYO 56B on the metal base ring. The straight wall envelope suggest European. Any ideas? Title: Re: Any idea what tube these are? Post by: KF7WWW on April 02, 2014, 12:40:29 AM I can't be sure but they look like EL34's better known as 6ca7's.
Title: Re: Any idea what tube these are? Post by: DMOD on April 02, 2014, 12:48:04 AM They may well be Mullard EL34 / 6CA7 and the SYO-56B is a date code.
Title: Re: Any idea what tube these are? Post by: N0WEK on April 02, 2014, 01:29:26 AM They may well be Mullard EL34 / 6CA7 and the SYO-56B is a date code. Good call guys! Date code reads "Feb 1956" Thanks! http://www.tube-classics.de/TC/Tubes/Valvo%20EL34/EL34.htm Eindhoven, NL Dec. 1954 - 1956 (1957?) Philips Valvo EL34 6CA7 with black metal base Einhoven SY0 SYO SYN code Code: 5XX SY0 or 5X SYN Identified by: - one piece disc getter - black metal base Comment: Very rare. SY0 Samples found from 54K until 56F, but also one from 57A (Jan. 1957) and SYNs: 5D and 5F Title: Re: Any idea what tube these are? Post by: Jim/WA2MER on April 02, 2014, 06:11:04 AM Before you put those in the junk box or install them in your Apache (or whatever else uses them), do yourself a favor and go to eBay to see what people will pay for used Amperex or Mullard metal base EL34s.
Title: Re: Any idea what tube these are? Post by: N0WEK on April 02, 2014, 12:21:52 PM Before you put those in the junk box or install them in your Apache (or whatever else uses them), do yourself a favor and go to eBay to see what people will pay for used Amperex or Mullard metal base EL34s. Yikes!!! I guess I should test these and list them over there. $600 for a used pair? The upside of Audiophools! Thanks! Title: Re: Any idea what tube these are? Post by: Jim/WA2MER on April 02, 2014, 12:33:22 PM Crap, I posted the wrong message! I meant to offer you $10 for the pair ;) AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
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