I’ve worked a bit on the electronics which will make it possible for us to have a radio on the same band as the runner, listening on the same band while the runner is not transmitting and thus making it easier for us to work multipliers and in-band qsos. The system will be interlocked and when the mult radio wants to work a multiplier it will use the amp from the runner, switched with a transfer relay. It will also have a priority switch, which handles the PTT function, with functions for “First wins”, “Radio 1 priority” or “Radio 2 priority”.

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Today I did some more work on the 2x4CX1500B amplifier. I added support for the L:s in the PI-filter and also fastened the V1V relays used to switch the tapping of the L. Now I need to build the clamps to hold the C2 capacitor and hopefully I will soon receive the axle couplings which will be used to hook up the stepper motors with the capacitors.

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I have worked some on the amp lately. Not much more has been done except some work getting ready for the CQWW CW contest this weekend. The ops will be me (SM2WMV), SM2LIY, SM3JLA and SE2T.

I’ve mounted the anode chokes, one which can be switched out with a V1V relay. This is to avoid any problems with internal resistances within the HF bands. I just use both the chokes on 160 and 80m, while I just use one of them on 40-10m.

I also made an L for the PI-filter, the first part of it which will be used for 10-20m, maybe also 40m. I tried to silver plate it and the recipe I found on ON7LR website. I also mounted the C1 capacitor which was donated by SM3BDZ. This is a 1000pF variable vacuum capacitor which is padded with a 500pF capacitor that is switched in with a V1V for the low-bands.

Now next step is to make a mounting bracket to hold the C2 capacitor, which is a 1200pF variable vacuum capacitor.

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I did do some work on the amplifier. I mounted a 2nd floor in the cabinet which will hold the PI-filter on the upper floor and the control electronics on the bottom floor. I also mounted the fan but I changed my mind. First I was going to use it to suck air through the amplifier but then I decided to move the heater transformers under the sockets which would make the hot air also go through there. So instead I will make it blow air into the amplifier and thus cool air will be pushed through the heater transformers. I also mounted the sockets and chimneys and hopefully this weekend I will start on the anode chokes.

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