W5FRS


The 40 Meter HK54 transmitter and 808 Modulator on 7160KC April 21, 2012

site top


100_9962.JPG
Modulator metering panel.
100_9963.JPG
Push-Pull 808 modulator.
18MB MOV file
Calling CQ40 - modulator plate meter action
(18MB MOV file)
lo-res 3MB AVI here
100_9967.JPG
Dennis has several home brew transmitters built and modified over decades of time. (more here)
100_9968.JPG
Looking at the modulator, about to check heat flow
100_9970.MOV
One way to check that the heat can rise away from the tubes.
(30MB MOV file)
100_9972.JPG
250TH transmitter, and an RME receiver for SWL.
100_9973.JPG
top to bottom:
1.)Lafayette ham receiver for spotting and some SWL
2.)Drake R-4's for AM and CW reception
3.)push-pull HK54 40-Meter RF amplifier
100_9974.JPG
top to bottom:
1.)solid state PA amp used as speech amp to drive 808 modulator
2.)Stromberg-carlson mike mixer
3.)Altec 1570B used to cathode modulate the 250TH.
100_9975.JPG
Above the audio equipment is the antenna matcher, and the VFO.
100_9976.JPG
VFO from pongrance.com mounted in a little box.
100_9977.JPG
Another transmitter, and above it the buffer for the VFO and above that the 40M driver with an 809, that drives the KH-54 RF amplifier.
100_9978.JPG
40M driver with an 809 as described in the video about the 40M station (below).
100_9979.JPG 100_9980.JPG
pron view of the 808 modulator and BC-610 modulation transformer.
100_9983.JPG
808's in the dark.
100_9984.JPG
Inside the 40M driver.
100_9985.JPG
Close-up of the untuned VFO buffer described in the video.
100_9986.MOV
Video describes all about the 40M transmitter and modulator.
(317MB MOV file)
lo-res 46MB AVI here

August 1, 2013