Repeater overload on summit?

On the Bands Operating Procedures
41

The T50-12 toroid has been replaced by a T50-17 Blue/Yellow. T50-17 Toroid, material 17, Synthetic Oxide, 20 to 200MHz, AL= 18uH 100 turns.

Mini-kits have stock.

Andrew VK1AD

42

Take vx6 radio to summit where there are commercial VHF transmitters.
Call CQ SOTA on VHF
Wonder why nobody calls you.
Call CQ SOTA on VHF again.
No replies.
Try UHF and lots of people said there was a pileup of VHF callers that you couldnā€™t hear.

43

VX-7 is the same.
73,
Rod

44

To VK3SQ: I own one of each, so they were among the first radios I tested.

First test was for desense. I generated a modulated signal on the receive frequency (146 MHz.), and set it for 20 dB quieting. Then, I injected a signal on 150 MHz. and slowly turned up the level until the receiver quieting began to drop. Noted reading. Then I turned up the 150 MHz. level more until the 146 MHz. signal disappeared and noted that. I also substituted other frequencies for the 150 MHz. signal.

Next, I chose signals far removed from 146 MHz. and tested for front end overload. I also tested with wideband adjacent channels within the ham band.

The VX-2 was among the worst receivers other than the chinese radios. It was much better than the chinese radios! The VX-6 didnā€™t do much better than the VX-2 but somewhat better. The Icom and Kenwood portables werenā€™t any better. I also tested my trusty old Standard C-558 portable and found it was much better than others, but still not as good as the HTX-202 or the Icom IC-2 portable. The ADI AT-201 was very good, and could be used for SOTA work also. I have 2 of them as backups for the RS and Icoms.

45

Iā€™ve just done a 2m HT activation on Long Mountain-Beacon Ring. The desense/ blanking / QRM was horrific - worst I recall experiencing, certainly on my FT70D.

Dreadful. Six contacts though, so not a total disaster. I had to work hard for each of them though!

46

Sounds to me it would have been easier to set up HF on there dad.

Jimmy M0HGY

1 Like
47

I was only out activating for around 20 minutes so still probably quicker to go 2m HT style.

The summit would be a good testing ground for filters.

2 Likes
48

Useful link on this topic: VHF/UHF handheld performance comparison | QRPblog

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49

Good video about overload/blocking on summits and demo of the sotabeams 2m filter: Bandpass filter for 2m - SOTABEAMS . Looks like DX Engineering carries them as well. Donā€™t have one, just passing along the info.
Jim/K7MK

1 Like