Friday, October 26, 2018

Something Old and Something New after Hurricane Michael

Fortunately, our home survived Michael fairly well and we have moved back in. I must start over with outside antennas because the trees came down. Actually, it will be easier to work amateur satellites from the backyard.

I have picked up some vintage treasures from eBay including an original Ameco AC-1. I also have an SDRPlay RSP-2 Software Defined Radio that I have not found a good use. So why not use the Ameco AC-1 to transmit and The RSP-2 for receive. I will need a transmit/receive switch to keep from damaging the SDR. For that, I am using an MFJ 1708B RF Sense SDR Receiver TR Switch. I am letting it switch on RF sense. The AC-1 is set up for 40 meters and uses crystals to set the frequency. I get four watts RF out.

Ameco AC-1
Being rock bound or crystal controlled can be challenging because pretty much you have to call CQ at 4 watts or get lucky that a station calling CQ is close enough to the crystal frequency to hear you. However, I happen to have a 7.123 MHz crystal which is the frequency for the daily Sun Rise CW net. The SRN net is friendly to all check-ins. They will remember you between check-ins and chat a bit. I QNIed this morning using the AC-1/SDR combo. I got a report of 339 but the NCS, K4AXF in Virginia, copied all my info and repeated it for the net.

SDR Play RSP-2 in the foreground.

I enjoy the glow of the 6V6 and the 6X5 tubes just like the novices did for their first QSO .way back when. You know the RSP-2 is a pretty good receiver for a little over one hundred dollars. I am using the free HDSDR software on my laptop. You could homebrew some transmitters and use the RSP-2 for the receiver. You can't monitor your transmitted CW with it because the SDR latency will throw you off. I need a mute circuit for an external speaker so I don't have to mute the speaker myself.

The MFJ SDR TR Switch

My antenna was my 30 ft horizontal, and 20 ft vertical loop fed a the bottom center. The lower wire is ten feet above the ground. Hurricane Michael took all my trees I used for antenna support. So this loop that I constructed for Field Day comes in handy. It uses three 31 ft Jackite poles for support. I already had an SGC tuner just outside the house back wall. I ran 300-ohm balanced feedline between the loop and the tuner. The antenna tunes nicely on 40, 30, 20, 17, and 15 meters.

The Field Day loop comes in handy after Hurricane Michael. It replaces the 132-foot doublet I had in the trees. Now no trees.

HDSDR software on the laptop

BTW, I used VIZ Isotap II Isolation and switched autotransformer to avoid getting shocked. I am not sure if it was necessary, but I did it anyway. If you are wondering I have several AC-1s. This one is an original and worked on the first try.

VIZ isolated autotransformer