After a lovely day on the moor, activating G/DC-001 (and a bonus 100 mile S2S with @G4TCU); I experimented with different radios/antennas on the summit and here’s what I have learned:
First of all, there is a lot of QRM on this summit. That said, with a decent radio you needn’t worry. I can’t say whether the QRM is consistent (ie whether it went up and down throughout the afternoon), but it was certainly there. It turns out that the radio mast on Yes Tor is only in use during MOD exercise - so it is coming from elsewhere.
When I first arrived, with the squelch off, I was reading QRM in the S5/S6 region on the FT-70d. Worried about my activation, I used my Sotabeams band pass filter which took it down to S1. Despite attenuation of TX & RX signals, I managed to activate the summit, having a S2S QSO with G4TCU on G-WB-008. I found out later that I needn’t have used the band pass filter.
Another bonus, I managed to QSO with M7PHG on GB-0008 (POTA), whom I could not communicate with the last time I was on this summit.
Testing:
There were various hams dotted around the South West for our Sunday afternoon net, but I settled on a station located at Woodbury Common who was static, using 25w on a mobile rig. All tests were conducted on 2m, apart from test 6 which was done on 2m and 70cm.
No filters were used for the test, and all radios had squelch set to S1. All radios were tested using the same equipment, apart from the FT-70d which needed a different SMA to BNC adaptor.
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1- Quangsheng UVK5 + Flowerpot = Overwhelmed. S meter was all over the place, station not readable. 60% of the time it was silent. Tiny bits of his over came through but not nearly enough to communicate. Out of interest, I put the Yaesu’s rubber duck on the Quangsheng and I was able to receive the station 53. A good option if your radio is overwhelmed, but you might not receive distant/weak stations.
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2- Tidradio H3 + Flowerpot = Overwhelmed. I could not read the S meter due to its colour screen in sunlight, but again the station was not readable. 75% of the time it was silent. Hardly anything heard from his over.
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3- Yaesu FT-65 + Flowerpot = Excellent. Broadcast quality, 59 and nothing strange happened. I’d be very happy to recommend this radio for SOTA. This will be my go to radio for activations (see point 4 below).
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4- Yaesu FT-70d + Flowerpot = Excellent. Broadcast quality, 59. I spent over one hour on this radio, and I did hear the occasional bit of intermod, but it didn’t interrupt RX. Had I spent longer on the FT-65, I might have noticed the same so I won’t deduct points… but the FT-70d’s battery life is where I will deduct points.
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5- Flowerpot vs Diamond RH770: I performed this test on the FT-65. I lowered the flowerpot to a height similar to what the RH770 would be at, and compared the two. Reports from more distant stations were that my flowerpot gave me slightly better TX, and I had slightly better RX. Only after the test, I noticed that by moving the flowerpot out of the way, I improved my RX slightly. It could be that I was too close to the flowerpot whilst making comparisons. More testing needed here, to give you more detailed S meter information.
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6- Diamond RH770 vs SRH771: I performed this test at a different location using the FT-65+RH770, and the FT-70d+SRH771. The RH770 was significantly better than the SRH771. The benefit was most pronounced on 2m. This makes sense, because I know that the SRH771 does better on 70cm than 2m. Whilst not as pronounced on 70cm the RH770 was still a lot better for TX and RX. Again, I will follow this up with S meter information, and I will take the time to use the same radio next time.
I wanted to do more testing, but I was getting rather cold. More to follow as I alluded to above.
For now, based on my observations, my SOTA kit will consist of:
1- FT65 as my main radio.
2- Flowerpot as my main antenna, especially because I can put it on a mast.
3- FT-70d as my backup radio.
4- RH770 as my second antenna - for use when I want something quick and easy to deploy.
