Many thanks to Bob (K7ZB) who shares the following guest post:

ATS-20 configured with Zachtek “Flea” CW transmitter

The ATS-20 in HF CW Transceiver Mode

by Bob Houf (K7ZB)

I picked up an ATS-20 last summer and played with it on SWBC and the ham bands but found the telescoping whip antenna to be marginal.

The unit I purchased from Amazon turned out to be solid: no problems have surfaced after 9 months of intermittent listening. By default, I have enjoyed it primarily listening to FM in my office.

When I used my long wire antenna, the performance on shortwave greatly improved – easy copy of DX and the value of the receiver began to impress me.

Recently I came across a Swedish ham who co-developed a line of radios covering a broad range of WSPR and associated designs built to a very high standard.

Already having a WSPR setup I was intrigued by a very low power CW transmitter that Zach co-developed with KB9RLW which puts out 300mW on 40, 30 and 20 meters at a price point that is less than the ATS-20, and – most interestingly – the design of the radio allows it to work in transceive mode with the receiver by providing a T/R switch when used with the proper SMA-BNC cable arrangement.

I bought a “Flea” and configured it with my ATS-20 then used an external antenna tuner to make sure the transmitter had close to a 1:1 SWR. The “Flea” advertises that it is robust to high SWR and looking over the schematic that is evident, but for the sake of a trial I went with the ATU. Continue reading Bob pairs his ATS-20 with the Zachtek “Flea” CW transmitter →