type 139 chinese receiver pwr slp question
 

Hi all;
I have the receiver working well with batteries, 90vdc for plates, and
1.5v for filaments, ..90v doesnt draw much I, but the I from the 1.5v batts
is 300ma.
I have acquired an acopian 120 volt dc power supply,
I would like to connect the output to a circuit, (hopefully something
simple)
that will give me 90v and 1.5 v.
any help greatly appreciated, I do have a good junkbox with resistors ,
the
old power types and 2 watt jobs,
tnx Jim kw3u
I figure why reinvent the wheel when I can be lazy and ask the experts
here.

type 139 chinese receiver pwr slp question
 

An OB3 voltage regulator tube and a resistor will provide
90V from 120V. So would a 90V zener diode or string of
lower voltage zener diodes in series and a resistor.

The 1.5V could be produced with a series string of silicon
rectifiers and a resistor (maybe two or three. It depends
on their forward conduction voltage.) The power lost in the
resistor(s) for this output voltage will be at least 35W.

For the 90V it's not a bad way to approach it. For the 1.5V
it's kind of crappy but it will work if the power supply can
provide enough power and you like the smell of hot resistors.

You might find the filament circuit in this design useful
and the 105V output could be turned down to 90V.

http://www.dwave.net/~twomules/vtpwr.pdf

If you eventually decide to build a dedicated off-line supply
for the radio this may help.

http://www.dwave.net/~twomules/smps.html


vy73


"Jade's Tech Services" wrote in
:

Hi all;
I have the receiver working well with batteries, 90vdc for plates,
and
1.5v for filaments, ..90v doesnt draw much I, but the I from the 1.5v
batts is 300ma.
I have acquired an acopian 120 volt dc power supply,
I would like to connect the output to a circuit, (hopefully
something
simple)
that will give me 90v and 1.5 v.
any help greatly appreciated, I do have a good junkbox with
resistors ,
the
old power types and 2 watt jobs,
tnx Jim kw3u
I figure why reinvent the wheel when I can be lazy and ask the experts
here.

type 139 chinese receiver pwr slp question
 

Jade's Tech Services wrote:
Hi all;
I have the receiver working well with batteries, 90vdc for plates, and
1.5v for filaments, ..90v doesnt draw much I, but the I from the 1.5v batts
is 300ma.
I have acquired an acopian 120 volt dc power supply,
I would like to connect the output to a circuit, (hopefully something
simple)
that will give me 90v and 1.5 v.
any help greatly appreciated, I do have a good junkbox with resistors ,
the
old power types and 2 watt jobs,
tnx Jim kw3u
I figure why reinvent the wheel when I can be lazy and ask the experts
here.




OM, I'll forward the schematic of the power supply I built for the
complete 102E radio set, which includes the Type 139 receiver. Given
you don't have the transmitter, its a bit simpler. Use your existing
power supply for B+ and locate a small, center-tapped 6.3v filament
transformer. Use, as I did, a Fairchild 1.5v 3A regulator. It makes the
circuit a bit simpler and provides regulation, of course. FYI, the
receiver will work well from anywhere from about 75 volts up to no more
than 120v DC. Its not necessary to regulate the voltage, either,
although an 0B2 or 0B3 VR tube may make obtaining the requisite B+
voltage a bit easier. If you'll pass on your direct info, I'll send you
a TIF of the schematic and some info from an article I did on the 102E
system. The info will give you the part numbers of the $4 Fairchild
TO-22 regulators.

de Jeep/K3HVG