|
Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
|
Thread Tools |
27th Feb 2006, 11:34 pm | #1 |
Administrator
Join Date: Dec 2002
Location: Cardiff
Posts: 9,071
|
Conversion of the HMV 904 to use a 5F4 CRT
I have just received the attached PDF document from Hugo Holden who feels it will be of interest to some of you and asked for it to be posted here.
|
28th Feb 2006, 12:25 am | #2 |
Pentode
Join Date: Feb 2004
Location: Columbus, Ohio, USA
Posts: 150
|
Re: Conversion of the HMV 904 to use a 5F4 CRT
5FP4s are relatively hard to find. Another tube that works well is the 5AXP4, which was the first universal test tube made in the U.S. They are easy to find and physically very similar to the 5FP4.
I used one of them to replace the CRT in our Pye 817 when the Emiscope 3/1 (not the original tube) that came with the set failed: http://www.earlytelevision.org/pye_817.html |
28th Feb 2006, 9:04 am | #3 |
Retired Dormant Member
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
|
Re: Conversion of the HMV 904 to use a 5F4 CRT
Thanks for this valuable information. I have a Marconiphone 706 (= HMV 904) and thankfully the CRT is still usable. It's far from perfect but I see no reason (yet) to make the set non-original just to get rid of the ion burn and get a bit more brightness. It might be worth acquiring a 5AXP4 against the day that my CRT fails.
|