Ok so I have one decent antenna - an indoor AL-705 loop. But I have three things I want to connect it to
* My ELAD FDM-DUO SDR transceiver, possibly via my MAT-125E auto ATU
* My QPR-Labs QCX+ WSPR transmitter
* My NanoVNA, for tuning and checking the SWR to the loop
So I am building a switching unit. And for fun I am putting in it a stupidly simple resistor SWR bridge, with LED indication for high/low SWR which will also help with loop tuning (in addition to the power meter described below which still is, for now, the best way of optimising the matching)
Here it is. Without the three way switch which will mount on the right & I have ordered but which has not yet arrived
The red switch bypasses the small SWR bridge. I chose this green LED after trying a bunch from my scrap box as the brightest of the bunch, there was a notable difference between LEDs. I have standardised, good or bad, on BNC connectors, they are so quick and easy to plug/unplug when fiddling about.
Project finished, works great, now can switch antenna from ELAD for FT8, U3S for WSPR and NanoVNA for tuning.
More outputs
A later modification expanded the outputs to four, for my QRP-Labs WSPR TX, my Xiegu G1M, my ELAD FDM-DUO and the NanoVNA. Very convienient
No comments:
Post a Comment