Too hot for SOTA

During the warmer months of summer I took the opportunity to catch up on some much need repairs and upgrades of my SOTA kit.

The Rig:



ATS4, when I built the ATS4 I chose to build it with 17m instead of 15m. I have made contacts on 17m but with the JA’s joining SOTA and since it is more likely that chasers will have beams for 15m than 17m I changed 17m to 15m. Not a big job, just change band filtering components, the band selection resistor and a re-tune.

While I had the rig apart I also change the DC socket to match my MTR, the ATS4 has 1.3mm and the MTR has an EIAJ-02 (1.7mm), I decide it would be simpler to have them the same to save any confusion. The EIAJ plug was chosen as it is a little smaller than the 1.3mm and appears to be a little more robust.


Coax Patch Cable:


RG-174 2m patch lead

I had purchased a few connectors from eBay to suit RG-174 cable, the RCA was fine but the BNC was tight when connected to a BNC socket, so the BNC plug was binned and a new one from a better supplier was fitted, and works much better.


CW for the SSB rig:


Oscilator and Keyer

I built an ILER 40 SSB kit early in my SOTA activities (, I have decided to add CW to it. After considering the options I have gone for an external audio oscillator. This one is from Walford ( in the UK and is still a work in progress.


Antenna Tuners:


Well used SLT Tuner and the home built ALT tuner

I have been using end fed antennas from day one, although I have changed from an end fed tuner (Qrp Kits SOTA tuner) to an L-Match. I am very happy with the L-Match arrangement, and I have used the QRP Kits SLT tuner for some time. I decide to look at a more weather resistant option, Ham Shop ( sells the PCB for the original SLT design by Steve KD1JV (

I have built this into a 2oz, Tabaco tin from eBay, the finished size is the same but with its lid on packs easier and the lid can also be left on (once adjusted) in the field to provide a little more weather protection. The switchable PCB links are from Element14 and the Banana extenders are from Dig-Key.

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