06-10-2016, 09:06 PM
(This post was last modified: 06-10-2016, 09:09 PM by Mike Watterson.)
No, the 1j29b are power devices, up to 150V anode volts. They will just about work at 30V. The 1j24b ( Less than £1 each in quantity!) or even 1j18b are far better at low voltage (18V is possible, though 24V is much better). They will be usable to replace B7G audio out in a 45V battery set, but far better in 67V and 90V sets.
More powerful than DL94 audio out, yet better at RF than DF97 or DC90
You only need 1/2 the filament on a 1j29b to replace a DL91 / DL92 / DL96 in a 1.4V set!
I mount the metal screen on a foam pad. I've not tested them for microphonics as such, but they are designed to survive vibration (not same thing).
Here is a subminiature very low power magic eye to suit.
http://golbornevintageradio.co.uk/forum/...p?tid=5891&pid=61978#pid61978
Note that ECH81 (=ECH83), EBF89, ECC82 and many more work off 12V to 14V HT and were used in car radios where heater current didn't matter. Used with transistor audio out. Earlier car radios used transistor inverter for 120V HT and before that they used vibrator to get 120V HT, so valve audio out was used.
More powerful than DL94 audio out, yet better at RF than DF97 or DC90
You only need 1/2 the filament on a 1j29b to replace a DL91 / DL92 / DL96 in a 1.4V set!
I mount the metal screen on a foam pad. I've not tested them for microphonics as such, but they are designed to survive vibration (not same thing).
Here is a subminiature very low power magic eye to suit.
http://golbornevintageradio.co.uk/forum/...p?tid=5891&pid=61978#pid61978
Note that ECH81 (=ECH83), EBF89, ECC82 and many more work off 12V to 14V HT and were used in car radios where heater current didn't matter. Used with transistor audio out. Earlier car radios used transistor inverter for 120V HT and before that they used vibrator to get 120V HT, so valve audio out was used.
