I didn’t count pins but today discovered the plastic sockets I tossed yesterday were not 9-pin mini but 8 pin rimlock.
Today I found the used Valvo tubes they held.
Valvo a pai of UF42, an EF42, and an ECH42..came out of a very old pre-WWII dielectric analyzer, which disintegrated (with some help) years ago... curious how old...have 4-letter codes below pn’s, and black info under base...
I thought it was odd all three types of tubes had the same numerals with different prefixes, but there is probably a reason other than OCD. I’d ask why, but think I lost interest since starting this post.
So now to offer them free to a good home, do I have to move this to Swap Meet?
Today I found the used Valvo tubes they held.
Valvo a pai of UF42, an EF42, and an ECH42..came out of a very old pre-WWII dielectric analyzer, which disintegrated (with some help) years ago... curious how old...have 4-letter codes below pn’s, and black info under base...
I thought it was odd all three types of tubes had the same numerals with different prefixes, but there is probably a reason other than OCD. I’d ask why, but think I lost interest since starting this post.
So now to offer them free to a good home, do I have to move this to Swap Meet?
ECH* is a Triode Hexode. UF*/EF* is a pentode.
U type valves have a 100mA heater, in the case of UF42 21volts. E type valves denote 6.3v heaters.
FYI;
The UCH42 is an early all glass triode hexode from 1948 and was designed as oscillator and mixer for superhet receivers, and the hexode section was designed to operate with an AGC control voltage. The 100 mA heater was intended for universal (AC/DC) sets, and this explains the low anode voltages. Mullard do not give a frequency range for this device, it is, therefore unlikely to be greater than HF as the valve predates VHF broadcasting by more than a decade. Mullard also say that the UCH42 may be used as a phase inverter. The ECH42 does the same job but with higher anode voltages and lower current.
The triode oscillator had to supply a peak to peak insertion voltage of 13 Volts.
U type valves have a 100mA heater, in the case of UF42 21volts. E type valves denote 6.3v heaters.
FYI;
The UCH42 is an early all glass triode hexode from 1948 and was designed as oscillator and mixer for superhet receivers, and the hexode section was designed to operate with an AGC control voltage. The 100 mA heater was intended for universal (AC/DC) sets, and this explains the low anode voltages. Mullard do not give a frequency range for this device, it is, therefore unlikely to be greater than HF as the valve predates VHF broadcasting by more than a decade. Mullard also say that the UCH42 may be used as a phase inverter. The ECH42 does the same job but with higher anode voltages and lower current.
The triode oscillator had to supply a peak to peak insertion voltage of 13 Volts.
Thanks, both.
I don’t think it’s as old as it looks...has Ruwido pots (gray pot metal ‘23’ bodies, flat riveted back covers with integral ‘ground’ tab on back. If it’s the same Ruwido founded in Austria in 1969...that doesn’t explain ‘Made in Germany’ & ‘Germany’ on other components...a lot of decades between de- & re-unification.
Some Elkonda capacitors have a DIN spec on them that was retired long ago.
Kopf air variable trimmer capacitors were another item observed, but I dead-end on that name.
Anyway, the hammertone green cabinet will house a tube amp some day.
HF sounds familiar...I vaguely think I got the idea it ran in the teens of MHz and there was nothing that looked like VHF layout to me. 50 pF trimmers probably more suited to HF, too.
Nothing but curiosity at this point...
I don’t think it’s as old as it looks...has Ruwido pots (gray pot metal ‘23’ bodies, flat riveted back covers with integral ‘ground’ tab on back. If it’s the same Ruwido founded in Austria in 1969...that doesn’t explain ‘Made in Germany’ & ‘Germany’ on other components...a lot of decades between de- & re-unification.
Some Elkonda capacitors have a DIN spec on them that was retired long ago.
Kopf air variable trimmer capacitors were another item observed, but I dead-end on that name.
Anyway, the hammertone green cabinet will house a tube amp some day.
HF sounds familiar...I vaguely think I got the idea it ran in the teens of MHz and there was nothing that looked like VHF layout to me. 50 pF trimmers probably more suited to HF, too.
Nothing but curiosity at this point...
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Immediately after WW2, it was not uncommon to build things with a mix of old and new components. As example, on my 1948 French Radiola push-pull amplifier the output tubes have the pre-war Europe side contact base, the rectifier has the even older 4 pin Europe base, the phase inverter is a frequency-converter triode/hexode wired in a creative way, and the preamp tubes have a Rimlock base (EF40). The volume potentiometer is clearly pre-war and the chassis is a strange cast aluminium part that seems to have been adapted from some areonautical military application/surplus.
I have a 1948 Zenith radio with an Octal, two Loktals, and a couple Miniatures.
Best radio in the house, FWIW. Pulls-in Boston clear, and NYC after dark listenable; all other radios just buzz except 3 local stations.
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