Bill Meara
December 31st 03, 09:49 AM
I thought you guys would like to hear about my current project:
40 meter double sideband transmitter. Solid State. To be used with my
Drake 2-B receiver. I wanted something that would allow me to contact
UK hams. My antenna will be low to the ground and NVIS should work fine.
I have kind of unusual VFO: Crystal controlled 10.1 Mhz oscillator mixing
with a 3.0-3.1 Mhz VFO. 40673 mixer. Produces 7-7.1 Mhz signal (European
40 meter ham band). I have two LC filters after the mixer to knock down
the 10.1 and 3 Mhz signals. I plan on letting the 3 Mhz VFO run all the time
(in both transmit and receive modes) -- I'll switch the 10.1 Mhz crystal
oscillator off when in receive mode.
Balanced Modulator is an NE602 using the circuit from the K2. This produces
a very nice deep null in the carrier.
I'm using a D-104 with the transistor amp in the base, so there was no need
for an audio amp in the rig -- D-104 goes directly into the NE-602.
RF amp is from a Doug DeMaw article in the Feb 1997 issue of CQ. Looks like
I'll be getting at least a few watts out.
I did the initial tests this morning -- all systems go. I should have it on
the air this weekend. It will have a real wooden breadboard for the base, and
an aluminium "kick panel" (for a door) for the cabinet.
I'll keep you all posted on progress.
73 from London. Happy New Year!
Bill M0HBR CU2JL N2CQR
40 meter double sideband transmitter. Solid State. To be used with my
Drake 2-B receiver. I wanted something that would allow me to contact
UK hams. My antenna will be low to the ground and NVIS should work fine.
I have kind of unusual VFO: Crystal controlled 10.1 Mhz oscillator mixing
with a 3.0-3.1 Mhz VFO. 40673 mixer. Produces 7-7.1 Mhz signal (European
40 meter ham band). I have two LC filters after the mixer to knock down
the 10.1 and 3 Mhz signals. I plan on letting the 3 Mhz VFO run all the time
(in both transmit and receive modes) -- I'll switch the 10.1 Mhz crystal
oscillator off when in receive mode.
Balanced Modulator is an NE602 using the circuit from the K2. This produces
a very nice deep null in the carrier.
I'm using a D-104 with the transistor amp in the base, so there was no need
for an audio amp in the rig -- D-104 goes directly into the NE-602.
RF amp is from a Doug DeMaw article in the Feb 1997 issue of CQ. Looks like
I'll be getting at least a few watts out.
I did the initial tests this morning -- all systems go. I should have it on
the air this weekend. It will have a real wooden breadboard for the base, and
an aluminium "kick panel" (for a door) for the cabinet.
I'll keep you all posted on progress.
73 from London. Happy New Year!
Bill M0HBR CU2JL N2CQR