Has anyone ever tried to make an amplifier for 6M, 2M, and 432 all in 1 box using a pair of 4CX250B tubes? If you have, what pitfalls am I looking at to do this?
Thanx
Vhf & Uhf Amp
Vhf & Uhf Amp
Stanley Lichtenberg
I have not built one.
However in looking at the HANDBOOK,i would think you would need to builld
3 discrete layers of amp, one for each band and stack them in the box,
with the final amp at one end.
I believe you would need to build different types of circuits for the three bands.
6 meters being the easiest ,basic coil and capacitor
while 2 m and 440 likley some for of strip line circuit.
band switching the final would also be a challenge...
However in looking at the HANDBOOK,i would think you would need to builld
3 discrete layers of amp, one for each band and stack them in the box,
with the final amp at one end.
I believe you would need to build different types of circuits for the three bands.
6 meters being the easiest ,basic coil and capacitor
while 2 m and 440 likley some for of strip line circuit.
band switching the final would also be a challenge...
That is pretty much what I thought as well. But I just thought in case someone tried it and said its impossible, I would build 3 separate amps. Just like to make 1 nice neat box was my thinking. Thanks for the reply. I have the winter to experiment and if I find something that works, I will write it up and share.
Thanks for the reply!
Stan
Thanks for the reply!
Stan
Stanley Lichtenberg
I mechanically visulize, three circuit boards, each for one band stacked with spacers an inch or so apart.
since an out put amp has likely only one stage, the 4cx250s then the three boards are just the input matching and tuning circuits.
then the switching necessary for the inpput to the '250s' and then an output tuneing circut, for each band. again a stack of three ...
the only thing common between the tree amps would be the 4cx250s and the high voltage and bias .
see if i can draw a picture.
--------------------------\ \----------\
/------------------------/ /----------\
/------------------------/ \--------\ O output
-------------------------\ tubes /--------/
/-------------------------/ /---------/
/-------------------------/ \--------\
power supply
six boards. 3 input tuning 3 output tuning.... tubes in the middle.
should fit in a 6 high 5 wide 10 long box,, plus power supply.
i wonder if the final of this will look like it does now.
. it doesnt. this program doesnt duplicate spaces exactly like i put them in.
should be longer gaps between the boards and then tubes in the second line in the gap. output on far right.
since an out put amp has likely only one stage, the 4cx250s then the three boards are just the input matching and tuning circuits.
then the switching necessary for the inpput to the '250s' and then an output tuneing circut, for each band. again a stack of three ...
the only thing common between the tree amps would be the 4cx250s and the high voltage and bias .
see if i can draw a picture.
--------------------------\ \----------\
/------------------------/ /----------\
/------------------------/ \--------\ O output
-------------------------\ tubes /--------/
/-------------------------/ /---------/
/-------------------------/ \--------\
power supply
six boards. 3 input tuning 3 output tuning.... tubes in the middle.
should fit in a 6 high 5 wide 10 long box,, plus power supply.
i wonder if the final of this will look like it does now.
. it doesnt. this program doesnt duplicate spaces exactly like i put them in.
should be longer gaps between the boards and then tubes in the second line in the gap. output on far right.