Repairing My VHF Delta Loop Antenna in Preparation for SSTV Event!

 An SSTV (Slow Scan Television) event from International Space Station is scheduled to start at 11:50 UTC on 11th November 2024 and will continue up to 18th November 2024. So there is plenty of opportunity to tune in to 145.800 MHz during the space station passes in our region and try to record the audio as well as decode SSTV images using Robot 36 app in our mobile phone in PD 120 format. As the transmissions are at relatively high power, most VHF reception setups will be able to get at least part of the SSTV images. Last time I could get partial copy even with a magnetic mount VHF antenna kept on my linear power supply. Ideal method of course, is to use a directional antenna pointed in the direction and elevation of the pass of space station continuously. But many of us may not have that. Doppler correction is also useful, but not mandatory to receive some images in high elevation passes.


I had used my recently homebrewed VHF Delta Loop antenna for local repeater contacts and a single contact through the FM transponder of International Space Station. As I had just fixed the delta loop on a piece of electrical wiring channel with insulation tape, it came down after a few days and this was the position of the delta loop. Delta loop has 210 cm 2.5 sq mm insulated copper wire fixed in the shape of a delta with 70 cm for each side so that it will act as a full wave loop for VHF and third harmonic resonance for UHF amateur radio bands. That is how I could work the cross band repeater on International Space Station with downlink on 145.990 MHz and uplink on 437.800 MHz using the delta loop antenna for VHF.

 

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