The most boring valves. - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Hunts smoothing bomb · 24th Sep 2014, 8:50 pm

I actually quite like the EF80, it has a construction with gaps in the anode enabling the onlooker to to see the large rectangular cathode glowing in the centre, same goes for the EF91.

The most boring valves to me are those octal american metal types and all D series battery valves.

Herald1360 · 24th Sep 2014, 10:37 pm

Quote:

Originally Posted by PJL

Anything that call itself a valve but has no glow - what madman invented the 0Z4, a valve without a heater?

I guess an 0Z4 would glow if it came in a glass envelope, but it would be even more difficult to shut in the RF hash that it generates. The damn things need near TEMPEST level screening to use in a receiver as they are.

kalee20 · 24th Sep 2014, 10:49 pm

Quote:

Originally Posted by merlinmaxwell

Sticks oar in, no valve is boring

I think there are degrees of boringness, the spirit of this thread is only comparatively boring compared with more interesting valves.

Placed alongside any s*m*c*nd*ct*r, ANY valve becomes an object of intense interest!

Tyso_Bl · 25th Sep 2014, 12:14 pm

Hmmm, yes I also like to nominate the American full metal jacket types, closely followed by the Mazda 10/20/30 types already mentioned. I'd like to defend the EF80 as I personally find it pleasing enough to look at, and functionally it will do anything you want, for a very long time.

Tyso

turretslug · 25th Sep 2014, 1:00 pm

'Tis a shame that the US metal octals (otherwise one of my favourite valve (toob?) series) don't proclaim their thermionicity a little more explicitly- though when working on an inverted chassis thus populated, one occasionally gets a glimpse of reassuring orange glow through vacant pin hole and glass base seal.

The poor old ubiquitous workhorse, the 6BA6/EF93, comes to mind. It doesn't have internal screen and 0.2A heater like the EF89, or lots of high HF gain, like the EF85 or EF183, or offer new ideas like the ECC84 or ECC189. It just sits in millions (well, lots) of radios doing a sort of OK job and similarly lots of miscellaneous boxes, overlooked in the quest for sexier bottles.

As an instinctive sympathiser with the under-dog, I always cross-reference encountered members of the afore-mentioned Mazda series just in case they're useful.

(And spell-check, how dare you quibble with "thermionicity"!)

daviddeakin · 25th Sep 2014, 3:21 pm

I also like the EF80. It has nice proportions; it's quitessentially 'valvey".

FERNSEH · 25th Sep 2014, 4:11 pm

How about these cuties? On the left the PC900 beam triode for television tuners and on the right the 6AK5 miniature RF pentode.
The 6AK5/EF95 is good for 400 Mhz. I've got lots of them and I must find a use for them.
You can't call the 6AK5 boring.

DFWB.

newlite4 · 25th Sep 2014, 4:23 pm

At least you can see the heater glow in an EF80 unlike its predecessor the EF50. Don't get me wrong, I appreciate that the EF50 (and its eqully boring stablemate the VR91) was the valve that won the war, but there are just so many of them around. As fast as you try to pass off a box of these valves, another 20 turn up on the bench seemingly out of nowhere. Horrible things!!!!
Neil

FERNSEH · 25th Sep 2014, 4:34 pm

And don't forget the Mazda SP61/VR65 did it's bit in the war. Besides that, it's an awful looking valve especially if you find one with the metalising flaking off.

DFWB.

kalee20 · 25th Sep 2014, 5:40 pm

Quote:

Originally Posted by FERNSEH

How about these cuties? On the left the PC900

With all respect, I'd say the PC900 is OT for this thread. It's just too cute.

FERNSEH · 25th Sep 2014, 6:00 pm

OK How about this boring lot? A box full metal tubes. These ain't cute.
I still think they great valves from the performance and reliability point of view.

DFWB.

Heatercathodeshort · 26th Sep 2014, 9:12 am

I had to laugh! I have an almost identical box of metal valves. Never used any of them. That fat red KK32 looks well out of place in that box, [would probably feel more at home in a 1940's lorry radio] and what about that bashed up EF50?
I really must finally sort these boxes in the nasty valves and odd ball shed. It's creepy in there especially after dark. I did a 'first sort' years ago but it never got any further. Plenty of unattractive junk to amuse us but all valves are nice are they not David? John

FERNSEH · 26th Sep 2014, 9:55 am

Hi John,
One couldn't call the KK32 boring, and it must be the fattest battery valve ever made. One of an interesting series of octal base 2 volt battery valves: KK32, KCF30, KF35, KBC32, KL35 and the KLL32. Essentially rebased pre-war valves. For example the KK32 is the octal version of the British seven pin base FC2A which in turn is a rebased Continental KK2. http://www.radiomuseum.org/tubes/tube_kk2.html

The American metal valves might look boring but they were the first of the then new international octal range of valves. Very advanced tech for 1935!
Glass versions soon followed.

DFWB.

Biggles · 26th Sep 2014, 10:30 pm

I've got a rather nice QY3-125 modulator bottle rescued from one of the Pye F300AM transmitters we had years ago at work but unfortunately it is u/s. It has sat happily gathering dust on a shelf in the shack since about 1987. We used to go through them at an alarming rate along with 4CX250Bs.

24th Sep 2014, 8:50 pm	#21
Hunts smoothing bomb Octode Join Date: Oct 2005 Location: Wimborne, Dorset, UK. Posts: 1,407	Re: The most boring valves. I actually quite like the EF80, it has a construction with gaps in the anode enabling the onlooker to to see the large rectangular cathode glowing in the centre, same goes for the EF91. The most boring valves to me are those octal american metal types and all D series battery valves. __________________ Lee

25th Sep 2014, 12:14 pm	#24
Tyso_Bl Hexode Join Date: Jul 2014 Location: Magor, Monmouthshire, Wales, UK. Posts: 436	Re: The most boring valves. Hmmm, yes I also like to nominate the American full metal jacket types, closely followed by the Mazda 10/20/30 types already mentioned. I'd like to defend the EF80 as I personally find it pleasing enough to look at, and functionally it will do anything you want, for a very long time. Tyso __________________ Adapt, Improvise, Oh Bother.....

25th Sep 2014, 1:00 pm	#25
turretslug Dekatron Join Date: Nov 2011 Location: Surrey, UK. Posts: 4,397	Re: The most boring valves. 'Tis a shame that the US metal octals (otherwise one of my favourite valve (toob?) series) don't proclaim their thermionicity a little more explicitly- though when working on an inverted chassis thus populated, one occasionally gets a glimpse of reassuring orange glow through vacant pin hole and glass base seal. The poor old ubiquitous workhorse, the 6BA6/EF93, comes to mind. It doesn't have internal screen and 0.2A heater like the EF89, or lots of high HF gain, like the EF85 or EF183, or offer new ideas like the ECC84 or ECC189. It just sits in millions (well, lots) of radios doing a sort of OK job and similarly lots of miscellaneous boxes, overlooked in the quest for sexier bottles. As an instinctive sympathiser with the under-dog, I always cross-reference encountered members of the afore-mentioned Mazda series just in case they're useful. (And spell-check, how dare you quibble with "thermionicity"!)

25th Sep 2014, 3:21 pm	#26
daviddeakin Hexode Join Date: Apr 2007 Location: W Yorks, UK. Posts: 407	Re: The most boring valves. I also like the EF80. It has nice proportions; it's quitessentially 'valvey".

25th Sep 2014, 4:11 pm	#27
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: The most boring valves. How about these cuties? On the left the PC900 beam triode for television tuners and on the right the 6AK5 miniature RF pentode. The 6AK5/EF95 is good for 400 Mhz. I've got lots of them and I must find a use for them. You can't call the 6AK5 boring. DFWB. Attached Thumbnails

25th Sep 2014, 4:23 pm	#28
newlite4 Octode Join Date: Nov 2003 Location: Bath, Somerset, UK. Posts: 1,805	Re: The most boring valves. At least you can see the heater glow in an EF80 unlike its predecessor the EF50. Don't get me wrong, I appreciate that the EF50 (and its eqully boring stablemate the VR91) was the valve that won the war, but there are just so many of them around. As fast as you try to pass off a box of these valves, another 20 turn up on the bench seemingly out of nowhere. Horrible things!!!! Neil __________________ preserving the recent past, for the distant future.

25th Sep 2014, 4:34 pm	#29
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: The most boring valves. And don't forget the Mazda SP61/VR65 did it's bit in the war. Besides that, it's an awful looking valve especially if you find one with the metalising flaking off. DFWB.

25th Sep 2014, 6:00 pm	#31
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: The most boring valves. OK How about this boring lot? A box full metal tubes. These ain't cute. I still think they great valves from the performance and reliability point of view. DFWB. Attached Thumbnails

26th Sep 2014, 9:12 am	#32
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: The most boring valves. I had to laugh! I have an almost identical box of metal valves. Never used any of them. That fat red KK32 looks well out of place in that box, [would probably feel more at home in a 1940's lorry radio] and what about that bashed up EF50? I really must finally sort these boxes in the nasty valves and odd ball shed. It's creepy in there especially after dark. I did a 'first sort' years ago but it never got any further. Plenty of unattractive junk to amuse us but all valves are nice are they not David? John Attached Thumbnails

26th Sep 2014, 9:55 am	#33
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,444	Re: The most boring valves. Hi John, One couldn't call the KK32 boring, and it must be the fattest battery valve ever made. One of an interesting series of octal base 2 volt battery valves: KK32, KCF30, KF35, KBC32, KL35 and the KLL32. Essentially rebased pre-war valves. For example the KK32 is the octal version of the British seven pin base FC2A which in turn is a rebased Continental KK2. http://www.radiomuseum.org/tubes/tube_kk2.html The American metal valves might look boring but they were the first of the then new international octal range of valves. Very advanced tech for 1935! Glass versions soon followed. DFWB. Last edited by FERNSEH; 26th Sep 2014 at 10:24 am.

26th Sep 2014, 10:30 pm	#34
Biggles Rest in Peace Join Date: Feb 2004 Location: Hexham, Northumberland, UK. Posts: 2,234	Re: The most boring valves. I've got a rather nice QY3-125 modulator bottle rescued from one of the Pye F300AM transmitters we had years ago at work but unfortunately it is u/s. It has sat happily gathering dust on a shelf in the shack since about 1987. We used to go through them at an alarming rate along with 4CX250Bs.