Saturday 13 March 2021 – working DX SOTA chaser stations in New Zealand and Indonesia, SSB voice mode.
Equipment – Yaesu 2m HT, Yaesu FT817ND, 7m telescopic pole, homebrew 40/20m inverted V linked dipole and an experiment with the use of a 10m length of RG-174 coax. I normally carry a 10m length of RG58AU.
Batteries – 8 x Ni-MH LADDA 2.450 Ah AA HR6 batteries
Logging – Lenovo Tab 3 running VK port-a-log
|00:01||VK1FELF||2m||FM||Elizabeth s59 r59 S2S VK1/AC-043|
|00:02||VK1FDNK||2m||FM||Tony s59 r59 S2S VK1/AC-043|
|00:03||VK1LH||2m||FM||Les s59 r59 S2S VK1/AC-043|
|00:05||VK1MCW||2m||FM||Bill s59 r59 S2S VK1/AC-037|
|00:21||ZL4BDG/P||20m||SSB||s56 r59 S2S ZL1/WL-016 2350 km|
|00:25||ZL3JD||20m||SSB||Phil s58 r43|
|00:26||VK5IS||20m||SSB||Ian s58 r57|
|00:28||ZL1TM||20m||SSB||Andri s58 r55|
|00:28||ZL1BYZ||20m||SSB||John s59 r55|
|00:30||VK5PL||20m||SSB||David s35 r53 933 km|
|00:31||VK5PAS||20m||SSB||Paul s59 r57|
|00:34||VK6XN||20m||SSB||s58 r51 3088 km|
|00:36||ZL2IFB||20m||SSB||Gary s58 r56|
|00:37||VK1LH||20m||SSB||Les s59 r59 S2S VK1/AC-043|
|00:52||VK3CAT||40m||SSB||Tony s58 r58|
|00:55||VK5UV||40m||SSB||Rod s58 r56|
|01:11||VK5AYL||20m||SSB||Sue s58 r51|
|01:13||YB1TIA||20m||SSB||Tia s58 r35 Indonesia 5453 km at 5 watts SSB|
|01:14||VK5CZ||20m||SSB||Ian s59 r58 977 km|
|01:20||VK1MIC/P||2m||FM||Wade s59 r59|
*Post update – If you are wondering? The center insulator is a cut-out section of 6 mm (1/4 inch) kitchen cutting board I purchased from a local supermarket. Drill three small holes on each side and thread the wire through each hole to create small loops. This technique is known as strain-relief. The RF socket is a BNC, 4 hole panel mount.
Note: Assuming a VSWR of 1:1, a 10m length of RG174 at 14 MHz has approximately 0.9dB loss and at 7 MHz 0.6 dB loss. If the power level is 5 watts into the coax, the power out at 14 MHz will be 3.9 watts.
A 10m length of RG58AU at 14 MHz has a loss of approximately 0.5dB. 5 watts in = 4.45 watts out at the antenna feedpoint.
Saving weight in the backpack by substituting RG58x MIL-Spec with RG174 is a compromise and the potential losses should be understood.
Was the experiment with RG174 coax worthwhile, yes it was. 🙂 Will I use RG174 in future SOTA activations? Yes, when I’m hiking 10 km or more and weight saving in the backback is desireable. 1 kg saved in equipment = an extra litre of water I can carry.
Oh, and just to be perfectly clear, I won’t use RG174 for VHF or UHF activations. 🙂