Modulator metering panel. |
Push-Pull 808 modulator. |
Calling CQ40 - modulator plate meter action (18MB MOV file) lo-res 3MB AVI here |
Dennis has several home brew transmitters built and modified over decades of time. (more here) |
Looking at the modulator, about to check heat flow |
One way to check that the heat can rise away from the tubes. (30MB MOV file) |
250TH transmitter, and an RME receiver for SWL. |
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 |
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. |
Above the audio equipment is the antenna matcher, and the VFO. |
VFO from pongrance.com mounted in a little box. |
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. |
40M driver with an 809 as described in the video about the 40M station (below). |
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pron view of the 808 modulator and BC-610 modulation transformer. |
808's in the dark. |
Inside the 40M driver. |
Close-up of the untuned VFO buffer described in the video. |
Video describes all about the 40M transmitter and modulator. (317MB MOV file) lo-res 46MB AVI here |
August 1, 2013