MW22-14C vs MW22-16 - UK Vintage Radio Repair and Restoration Discussion Forum

EF80TVVALVE · 16th Nov 2021, 10:48 pm

Hi all

I'm back on the TV22 that I've been restoring for a little while, it's not been my main concentration so it's taken a long time to get to this stage. Upon powering up last night I found that the CRT was gassy. I have a Mullard MW22-14C spare, this has an identical 12 pin base but no aquadag coating on the outer glass. Can anyone confirm if the pin connections are the same on the 14C as they are on the 22-16? I can't seem to find any data for the MW22-14C, only the MW22-14 which has an earlier 8 pin connection.

Jac · 17th Nov 2021, 8:23 am

Doesn't the MW22-14(C) have an 8-pin base?

Jac
p.s. the MW22-14C is the same as the MW22-14 except there is no aquadag outer layer.

Heatercathodeshort · 17th Nov 2021, 9:33 am

It will interchange OK. Don't worry about the lack of coating. Adding a smoothing capacitor will do very little if anything. The MW22-16 has a duodecal base and requires an ion trap. J.

EF80TVVALVE · 17th Nov 2021, 10:53 am

Thanks for the replies both, I did make a mistake and it looks as though it is actually an MW22-17, the gun looks to be straight so I presume no ion trap magnet is required on it. I fitted the tube last night but haven't yet powered the set up, we'll see what sort of state it is in soon!

FERNSEH · 17th Nov 2021, 11:38 am

According to the Mullard Maintenance Manual the MW22-17 is identical to the MW22-16 except the MW22-17 has no ion trap and external coating.
Assume that the MW22-17 has the duodecal base?
Attachments show information for the MW22-14 and MW22-16.
MW22-14 has the eight pin B8G base, similar to the base on the 7S7 valve.

DFWB.

EF80TVVALVE · 17th Nov 2021, 12:09 pm

Lovely stuff David, it certainly does have a duodecal base. It's an unknown tube and the neck looks pretty roasted, but the heater and vacuum is good so fingers crossed its a good one. I had one in a PYE just like this and it turned out to be an excellent tube, despite its rather poor appearance.

murphyv310 · 17th Nov 2021, 11:26 pm

You cannot really go by appearance, for example I look like 130 but I'm only 67..... I'll get my coat.

Have fun.

16th Nov 2021, 10:48 pm	#1
EF80TVVALVE Octode Join Date: Feb 2010 Location: Leicester, UK. Posts: 1,433	MW22-14C vs MW22-16 Hi all I'm back on the TV22 that I've been restoring for a little while, it's not been my main concentration so it's taken a long time to get to this stage. Upon powering up last night I found that the CRT was gassy. I have a Mullard MW22-14C spare, this has an identical 12 pin base but no aquadag coating on the outer glass. Can anyone confirm if the pin connections are the same on the 14C as they are on the 22-16? I can't seem to find any data for the MW22-14C, only the MW22-14 which has an earlier 8 pin connection.

17th Nov 2021, 8:23 am	#2
Jac Heptode Join Date: Jun 2006 Location: Eindhoven, Netherlands. Posts: 642	Re: MW22-14C vs MW22-16 Doesn't the MW22-14(C) have an 8-pin base? Jac p.s. the MW22-14C is the same as the MW22-14 except there is no aquadag outer layer.

17th Nov 2021, 9:33 am	#3
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: MW22-14C vs MW22-16 It will interchange OK. Don't worry about the lack of coating. Adding a smoothing capacitor will do very little if anything. The MW22-16 has a duodecal base and requires an ion trap. J.

17th Nov 2021, 10:53 am	#4
EF80TVVALVE Octode Join Date: Feb 2010 Location: Leicester, UK. Posts: 1,433	Re: MW22-14C vs MW22-16 Thanks for the replies both, I did make a mistake and it looks as though it is actually an MW22-17, the gun looks to be straight so I presume no ion trap magnet is required on it. I fitted the tube last night but haven't yet powered the set up, we'll see what sort of state it is in soon!

17th Nov 2021, 11:38 am	#5
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: MW22-14C vs MW22-16 According to the Mullard Maintenance Manual the MW22-17 is identical to the MW22-16 except the MW22-17 has no ion trap and external coating. Assume that the MW22-17 has the duodecal base? Attachments show information for the MW22-14 and MW22-16. MW22-14 has the eight pin B8G base, similar to the base on the 7S7 valve. DFWB. Attached Thumbnails

17th Nov 2021, 12:09 pm	#6
EF80TVVALVE Octode Join Date: Feb 2010 Location: Leicester, UK. Posts: 1,433	Re: MW22-14C vs MW22-16 Lovely stuff David, it certainly does have a duodecal base. It's an unknown tube and the neck looks pretty roasted, but the heater and vacuum is good so fingers crossed its a good one. I had one in a PYE just like this and it turned out to be an excellent tube, despite its rather poor appearance.

17th Nov 2021, 11:26 pm	#7
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,422	Re: MW22-14C vs MW22-16 You cannot really go by appearance, for example I look like 130 but I'm only 67..... I'll get my coat. Have fun. __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member