22 May 2010

Military radios

On May 15-16 a fair for game hunters was held near Örebro in Sweden. On display were the Swedish Civil Guard and its partner FRO, The Swedish Voluntary Radio Organisation. There I met Björn SM4UOM and Maria SM4FXR showing some radios in use by the FRO. The closest two green radios are the Ra 145 VHF FM transceivers, 30.00-75.95 MHz and 920 channels. The Swedish army bought them from USA in the 60´s (PRC-25). The green radio behind the two Ra 145´s is the Ra 180 developed and built by Ericsson in the 80´s. It can be used for FM and data traffic. It was a rather sophisticated radio at that time using e.g.frequency hopping techniques. Frequency range is 30.0 to 87.975 MHz and 2,320 channels. The radio to the right is a somewhat modified ICOM IC-707 HF transceiver.

Nice weather radio setup

Summer is approaching here and it is time to test som ham radio equipment for comfortable outdoor use.  When it is nice weather of course :-) Last autumn I bought a military surplus antenna mast from the 70´s. It consist of four 2 m glass fiberglass tubes which makes the mast height 8 m. The weight of the complete package is only 10 kg. I tried to raise the complete 8 m mast by myself. I couldn´t. It was to dangerous. Even with three sections I found it difficult. You must be two to raise the complete mast. Two sections is more comfortable and then you do not need any guy wires just an earth anchor screw. The antenna manual (in Swedish) can be downloade here.

And this is the trial result in my little garden. The 6 element homebrew yagi on top of the two sections antenna 4 m mast.

And here in the garden in this sunny and warm morning on May 21 I had a ring QSO on 144.286 MHz with Seth SM0AGP, "Rolle" SM0EZZ, "Kurre" SM5RT and Thord SM4BDQ.

Below is a video recording when receiving the 144.412 MHz beacon SK4MPI near Borlänge in Sweden. The distance from my home QTH in JO99bd to the beacon in JP70nj is 218 km and the bearing is 311 deg. The beacon e.i.r.p. is 1,500 W, QTF is 45/315 deg and its antenna system 4x6 el yagis.