600 Meter
(VLF)
Experiments
as
WD2XSH/22
Transmitters
Low frequency work from a
transmit standpoint, requires a stable
transmitter, preferably
with a decent output power level. I felt the antennas would need to be usable for send
and receive work and started putting together my design for a few test jobbies.
Front Panel needs a little cleaning.
The ANTENNA connection on top.
The bottom shelf is the M.O. the next shelf up is the amplifier driver.
This shelf is the pair of 211 tubes. The manual states
that this transmitter will supply 200 watts of RF to its
rated antenna type and impedance.
close up
The "Rescued" H.V. Power Supply
Photos are here.
Then of course there is the much maligned
BC-375 with the TU-26 LF tuner
and
The BC-306 antenna Coupler.
The tuner plug-in covers the 500 Kc.
portion that the 500KC group is assigned.
Its range is from 200 Kc. to 500 Kc.
There is actual stable output up to 550 Kc.
From "THIS" unit!!
And the BC-306 antenna tuner ONLY works for
The frequencies covered by the TU-26B
plug-in tuning unit in conjunction with it!
If you are planning on using the BC-375(*) as a
transmitting element get the original manual here!
Took a little cleaning up and testing for this one.
Also make sure to open it up and see if all the
parts are inside, and connected to the right places!
with a decent output power level. I felt the antennas would need to be usable for send
and receive work and started putting together my design for a few test jobbies.
With a varied selection of exciters that
double as test equipment, all of which is controlled with their GPIB
interface capacity.
The PTS-040 dc to 40 MHZ
After clean-up
The HP-8640B DC to 512 Mhz
The HP 3336A Synthesizer/Level Generator.
With output levels to -115 Dbm.
Which accepts both Amplitude and phase modulation inputs. Here is AM.
Also the Frequency readout.
The ITT Mackay MR337-32A Exciter.
This Exciter provides 100 Milliwatts as a driver stage, with CW/AM/SSB modes.
The HP 461A adjustable gain Amplifier/Driver
for the Kalmus Amplifier.
After clean-up
The HP-8640B DC to 512 Mhz
The HP 3336A Synthesizer/Level Generator.
With output levels to -115 Dbm.
Which accepts both Amplitude and phase modulation inputs. Here is AM.
Also the Frequency readout.
The ITT Mackay MR337-32A Exciter.
This Exciter provides 100 Milliwatts as a driver stage, with CW/AM/SSB modes.
The HP 461A adjustable gain Amplifier/Driver
for the Kalmus Amplifier.
I use these to drive the KALMUS LA500H 0 -54 Mhz
solid state amplifier. Adjustable power output from 0 to 500 Watts
into a 50 ohm load. It is linear over the entire range, with a constant power level out which drops at 55 Mhz.
into a 50 ohm load. It is linear over the entire range, with a constant power level out which drops at 55 Mhz.
As for TUBE-Type transmit capability, and high power
capability, I use the following units.
First off is the RMCA ET-8010A,
which was restored to 600 meter operation some time back in preparation
for the
500
KC experiment. The unit is a M.O.P.A. rig that covers 300 to 600 Khz
easily.
Front Panel needs a little cleaning.
The ANTENNA connection on top.
There are (5) five switch frequency settings,
controllable after tuning
by the front panel switch, I will have to get the frequency
plates made now for sure. The lineup is an 807 oscillator, with an 807 driver to a pair of 211 amplifier tubes in parallel.
plates made now for sure. The lineup is an 807 oscillator, with an 807 driver to a pair of 211 amplifier tubes in parallel.
The bottom shelf is the M.O. the next shelf up is the amplifier driver.
This shelf is the pair of 211 tubes. The manual states
that this transmitter will supply 200 watts of RF to its
rated antenna type and impedance.
The front panel metering tells the
full story.
close up
The "Rescued" H.V. Power Supply
Photos are here.
Then of course there is the much maligned
BC-375 with the TU-26 LF tuner
and
The BC-306 antenna Coupler.
The tuner plug-in covers the 500 Kc.
portion that the 500KC group is assigned.
Its range is from 200 Kc. to 500 Kc.
There is actual stable output up to 550 Kc.
From "THIS" unit!!
And the BC-306 antenna tuner ONLY works for
The frequencies covered by the TU-26B
plug-in tuning unit in conjunction with it!
If you are planning on using the BC-375(*) as a
transmitting element get the original manual here!
Took a little cleaning up and testing for this one.
Also make sure to open it up and see if all the
parts are inside, and connected to the right places!
If you are cruising E-bay in the scientific instruments
sections, keep your eyes open for VARIAN amplifiers for the old MASS
Spectrometers. They packaged as a pair in the main control rack cabinet. Because folks, this unit sports a pair of 4CX250Bs
and can tune from 400 Khz to around 2.5 Mhz. The power supplies are in a separate chassis and usually DO NOT come with the
unit. However the specs for the 4CX250B are >Here<, and it is fairly straight forward to build the HV and screen and bias power
supplys if you have a reasonably large Junque box.
Spectrometers. They packaged as a pair in the main control rack cabinet. Because folks, this unit sports a pair of 4CX250Bs
and can tune from 400 Khz to around 2.5 Mhz. The power supplies are in a separate chassis and usually DO NOT come with the
unit. However the specs for the 4CX250B are >Here<, and it is fairly straight forward to build the HV and screen and bias power
supplys if you have a reasonably large Junque box.
The amplifier and exciter board.
Exciter board and bias and
screen voltage adjustments.
The schematic along with the adjustment
procedure for moving the frequency,
and the frequency range of the amplifier.
It is broken into three sections, and is full size.
Section-1, Section-2, Section-3
You can print them out and paste them together
to recover the full schematic.
A power one or AC/DC power supply
can be used for the screen supply, with
another used for the bias supply.
They will require that you change a resistor to
get the proper voltages.
Exciter board and bias and
screen voltage adjustments.
The schematic along with the adjustment
procedure for moving the frequency,
and the frequency range of the amplifier.
It is broken into three sections, and is full size.
Section-1, Section-2, Section-3
You can print them out and paste them together
to recover the full schematic.
A power one or AC/DC power supply
can be used for the screen supply, with
another used for the bias supply.
They will require that you change a resistor to
get the proper voltages.
Back to 600 Meter Page