UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Amateur and Military Radio

Notices

Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment.

Closed Thread
 
Thread Tools
Old 27th Jan 2014, 9:06 pm   #1
QWENIX
Pentode
 
QWENIX's Avatar
 
Join Date: Jan 2006
Location: Amsterdam, The Netherlands
Posts: 180
Default CV4064 S6F33 which brand?

Hello members,

I am looking for 4 x S6F33 valves NOS/NIB. I have seen STC or ITT and AEI (Ediswan Mazda Brimar) brands on the ebay.

Did Mullard also produce these S6F33. If you had to choose a brand made in England what brand would you prefer and why.

I am looking for these types for my 3x Racal RA17L and 1 Racal RA117E.

best regards, Qwenix
QWENIX is offline  
Old 27th Jan 2014, 9:14 pm   #2
GrimJosef
Dekatron
 
Join Date: Sep 2007
Location: Oxfordshire, UK.
Posts: 4,310
Default Re: CV4064 S6F33 which brand?

The valve museum says the S6F33 is 'sensibly equivalent' to Mullard's M8196. I don't know if this is true. But if you want to check through the M8196 datasheet then it's here http://frank.pocnet.net/sheets/129/m/M8196.pdf.

Cheers,

GJ
GrimJosef is offline  
Old 27th Jan 2014, 9:17 pm   #3
G6Tanuki
Dekatron
 
G6Tanuki's Avatar
 
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: CV4064 S6F33 which brand?

To be honest, I wou;dn't worry about particular brands.

In a well-designed piece of equipment the valves will not be operating anywhere near the edges of their performance-characteristics.

STC, ITT and Brimar were all essentially parts of the same operation: in the 1950s and 1960s Brimar was the primary "Consumer" brand while valves for commercial/military applications were sold with STC branding in the UK/Europe and ITT in the 'states..

Ediswan/Mazda and Thorn/AEI were the same company too. I've got a diagram somewhere which shows the various corporate mergers [including "Micromesh" and "BSA" valves and the link with the Kolster-Brandes company]
G6Tanuki is offline  
Old 27th Jan 2014, 9:20 pm   #4
FERNSEH
Dekatron
 
FERNSEH's Avatar
 
Join Date: Mar 2005
Location: Gateshead, Tyne and Wear, UK.
Posts: 7,444
Default Re: CV4064 S6F33 which brand?

The 6AS6 is said to have similar characteristics as the 6F33. That is special suppressor properties, not sure if it has the internally connected diode though.

http://www.r-type.org/exhib/aaa0063.htm

DFWB.
FERNSEH is offline  
Old 28th Jan 2014, 1:03 pm   #5
G8HQP Dave
Rest in Peace
 
Join Date: Sep 2008
Location: Solihull, West Midlands, UK.
Posts: 4,872
Default Re: CV4064 S6F33 which brand?

IIRC the 6AS6 and the 6F33 have different pinouts. Some receivers were made in slightly different versions for the US and European markets, so local spares could be used.

I believe the 6AS6 was a modified 6AK5/EF95, while the 6F33 was a modified EF91. I'm not sure which prototype the M8196 was based on. A photo might tell you, as the modified valves look almost identical internally to the unmodified version - and an EF95 looks quite different from an EF91.

My guess is that all genuine 6F33 came from the same UK factory, whatever brand they were wearing.
G8HQP Dave is offline  
Old 4th Feb 2014, 9:45 am   #6
Radio Wrangler
Moderator
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,801
Default Re: CV4064 S6F33 which brand?

The RA117 was made for theNorth American market and the original valve type selection was for availability in that region.

I once bought a brand new RA117, still sealed. It had 6AK5s in it and E180F mixers.

Racal weren't picky about makes, their purchasing department sourced valves at the best prices and the quality department worried mostly about MTBF. The subsequent military users were just the same over buying spares. The valves were within specification, and the receivers were within specification.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is online now  
Old 4th Feb 2014, 10:26 pm   #7
WME_bill
Octode
 
Join Date: Oct 2007
Location: Exeter, Devon, UK.
Posts: 1,553
Default Re: CV4064 S6F33 which brand?

M8196/6AS6. I have a Mullard published equivalents booklet 1967/8 which puts M8196 =CV4011=the US 5725=6AS6W. All special quality, with identical electrical characteristics, but the US versions are not necessarily identical assessment specifications.
The 6F33 has an internal diode protecting the suppressor, and was the minature B7G version of the Mazda 6F32=VR116 on the infamous Mazda Octal base. Much used in radar in the war. Ideal for the versions of the transitron/phantastron/sanitron timebase, developed by Fleming Williams and Moody about 1940. I suspect the valve was specially developed from the SP61. It has the same very heavy heater current.
The 6AS6 has no diode, and appears derived from the 6AK5. Made here by Mullard. Earlier, the Mullard EF50 was almost as good for dual control, though what one could call the minature B7G version, the EF91, was not so closely controlled, and is very variable.
There was even an improved version of the 6F33= CV329, which was later introduced as CV2209, but still under same civilian number , or perhaps it was just a special quality version as S6F33. Suggests it was difficult to control the g3 characteristics in production.
wme_bill
WME_bill is offline  
Old 6th Feb 2014, 12:35 pm   #8
QWENIX
Pentode
 
QWENIX's Avatar
 
Join Date: Jan 2006
Location: Amsterdam, The Netherlands
Posts: 180
Default Re: CV4064 S6F33 which brand?

Thanks for all the answers.

I managed to buy a lot of S6F33 (used/new mix about 50 pieces). Brands:

ITT (blue/green turqois print) and STC's black and white print. Some of them show the broad arrow symbol.

The S6F33 = CV4064 is a special ruggedized version with different specs regarding the 6F33 =CV2209 and also different specs regarding the 6AS6. The 6AS6 has a different pinout regarding G2 and G3 S6F33.

The CT160 AVO valve data shows testingsettings. But I also want to try testing these on my TV7D/U american army valve tester. Regarding the 6AS6 settings it is quite easy to set all the pin switches for the S6F33.

But the trouble is the bias/shunt settings, which testing procedure button to choose B? D ? and what number range ?, and how much is the minimal value which determins good or bad?
QWENIX is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 1:36 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.