Johnson 6n2
 

Has anyone done a mod to make a linear amp out of a johnson 6n2 Sounds
like a nice project

Johnson 6n2
 

The Johnson 6N2 may not be the best choice for a linear amplifier
conversion, although I am not sure what you mean. If you mean to use the
cabinet to build a low band amplifier, it seems like it would be easier to
start over. If you mean for vhf use, the output tube does not have a lot of
plate dissipation, so would not be a good linear amplifier for the vhf bands
either.

It would be more easily converted to a transverter, which could also be more
useful.

There seems to be a bit more interest in 6 meter am, and the unit may be
more valuable as is.

Colin K7FM

Johnson 6n2
 

On Wed, 8 Nov 2006, JB wrote:

Has anyone done a mod to make a linear amp out of a johnson 6n2 Sounds
like a nice project



I'm presuming you are talking about the 6N2 100 watt xtal controlled
transmitter (and not the Johnson 6N2 Thunderbolt VHF KW amp) originally
meant as an outboard unit for the Ranger (to get DC and modulation power)
to get on 6 or 2, AM/CW.

IIRC, that rig has a 40 watt plate disipation 5894 dual tetrode in the
final (push pull, with neutralization).

For linear operation, the only mods you would need would include DC bias
for the control grid, and fairly well regulated screen grid voltage
(necessitating some disconnection of, IIRC, a clamp tube that protects the
5894 against loss of drive-generated control grid bias).

You would have to look at a schematic to identify anything else that would
need changing. The rig has an oscillator-multiplier string with tuned
circuits for frequencies far from the 6 and 2 meter bands, so you would
need to feed excitation into the 5894 at the push-pull input RF
transformer rather than somewhere else.

Johnson 6n2
 

Thank you for your replies : I have several low output rigs (
Ten-Tech526 , Yaesu Ft620B). My thougts were to make a linear amp out
one of the two 6n2 that I have.(ssb) Either using the original 829 B
or changing to another tube. The output circuit looks so good , I do
not mind changing anyting in this rig it will just be a 6 meter or 2
meter amp. The other 6n2 would be for just AM, doing away with External
modulator, just adding a external power supply Well these
are my ideas Note: 6n2's cost under $30 so no big loss Tnx JB