Six tube rig with VFO

by OH6DC

Top left:

3.5 MHz VFO using ECC85 and EF89 tubes. Circuit is based on "McCoy VFO" by W1ICP (QST February 1962). The VFO is stable after warm-up of about 30 minutes.

Bottom left:

A separate high voltage power supply for the VFO. Eliminates all chirp in TX signal.

Center top:

3.5 MHz CW transmitter using EL84 and EL86 tubes. Circuit is based on 1950's novice transmitter, as described in a Finnish book "Uusi radiokirja" by Osmo A. Wiio and Unto V. Somerikko (1958).

Center bottom:

A dummy cabinet. I wanted the transmitter in line with the VFO and receiver. By the way, all cabinets are made of recycled PC power supply boxes. A piece of aluminium sheet was glued to cover holes in the front panel.

Top right:

3.5 MHz receiver using ECC85 and EL86 tubes. Cicuit is based on "The Regen-o-flex receiver" by Dave Schmarder.

Bottom right:

High voltage power supply for TX and RX.

Inside view, from left to right: VFO, TX, RX.

I built this rig in year 2012 and used it in a Finnish homebrew rig event called "ITE-tapahtuma".

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