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Potential backup 80m WAB Net frequency

PostPosted: Wed Jun 07, 2017 6:26 pm
by g0akh
After discussion at the WAB AGM prompted by Steve G4HPE, views are being sought about a backup frequency for 80m due to the 'pip' that spreads over the current net frequency of 3.760MHz (+/- QRM)

Several things have to be borne in mind, including the narrow band available to Mobile operators due to antenna limitations, other band users with long established net frequencies, and other forms of QRM.

Please use this thread to make suggestions/observations etc. for possible alternatives so it can be looked into further.

It would be useful to get views from mobile & portable stations as they are likely to be the ones affected most by changing frequencies.

Many thanks.

73,
Kev G0AKH

Re: Potential backup 80m WAB Net frequency

PostPosted: Thu Jun 08, 2017 8:21 am
by G7afm
Hi Kev
This has been talked about a lot on air lately,it does seem the most obvious solution for evening nets,from a mobile/portable activators few it would not be to much of a problem to retune a mobile whip with enough notice of using a differnt frequency,would not be something easy done when on the move with no auto ATU ,unless antenna has been pre marked and you can safely pull over to adjust.
As for portable again no ATU personally i use a 4 band linked dipole so everything is pre cut to desired segment of the bands so not going to be able to vary much from set frequency.
Be interesting to see where this goes.

Re: Potential backup 80m WAB Net frequency

PostPosted: Thu Jun 08, 2017 8:46 am
by daffyd
Hi, with my current rubbish antenna, I can only hear the 'pip' now and again, and it is strongest on 7.158, I have tuned around this week, and think that somewhere between 3.740 - 3.755 would be a start for a back -up frequency ?

DAVID
G0FVH.

Re: Potential backup 80m WAB Net frequency

PostPosted: Thu Jun 08, 2017 8:52 am
by g4iar
Surely this is not a problem with a dipole, Phil? My portable linked dipole has a bandwidth of over 200 kHz, where the SWR is less than 1.5:1.

The main problem, of course, is going to be for mobiles and what we're looking at is a clearish spot, not too far away from the nominal frequency, where there are no regular stations that just start up, regardless of what's already there. A big ask, we know!

Re: Potential backup 80m WAB Net frequency

PostPosted: Thu Jun 08, 2017 9:37 am
by G7afm
Never actually checked the bandwidth on the linked dipole so next time it,s deployed ????? will see how wide i can go,
not that it,s getting much use.

Re: Potential backup 80m WAB Net frequency

PostPosted: Thu Jun 08, 2017 10:20 am
by g4due
To be honest from my point of view a backup frequency is essential if I am to operate on 80m after dusk. In the far south east the pip is usually about 20db over S9 and I suppose my hearing is a tad sensitive to regular noise. 3.765 is about clear and should be OK. Just a thought, would it not be simpler to just move the net frequency?
73's
Adrian G4DUE

Re: Potential backup 80m WAB Net frequency

PostPosted: Thu Jun 08, 2017 10:46 am
by g4iar
Simpler - but bear in mind the large stock of paperwork we carry with 3.760 printed on it!

3.765 is too close to the preferred frequency of the Old Timers of 3.763. Remember - they don't have VFOs!

Re: Potential backup 80m WAB Net frequency

PostPosted: Thu Jun 08, 2017 12:38 pm
by 2W0XOT
It's not a big problem with my Ampro whips as the adjustment can be marked on the whip part with a small score, and alternatives can be marked also. Then all you need is the hex key for a quick change. I realise other antennas might not be so easy.
73 John MW0XOT

Re: Potential backup 80m WAB Net frequency

PostPosted: Thu Jun 08, 2017 1:30 pm
by G7afm
As you say John not really a big issue with the Ampro,so long as you know what frequency everyone else is on ,HI

Re: Potential backup 80m WAB Net frequency

PostPosted: Thu Jun 08, 2017 7:14 pm
by GI0AZB
We are really interested in this discussion, more from the portable but also from the mobile aspect. On the portable side we use 80M where we can on WAB either from SOTA, Trigs or HuMPs. A change in frequency wouldn't cause us too much grief as we mostly use the home made end fed long wire with a portable ATU. This last few months Esther has had to revert to other bands close to 80M to save the day so anything to help on the 80M portable would be a bonus. My main interest on 80M is the mobile action. Having to be at work during the day any night time activations is usually 80M mobile. It would be no grief for me to readjust the mobile set up if a new frequency was decided upon. This last few outing we have found some ops on 3.761 / 2, so perhaps around that would be a choice. Of course there are other nets around that as well, namely I think 3.763 but not 100% sure. Is it an option to slip down a few Kcs, I haven't seen many ops doing that on 80M for a while. Anyway, please let us know what is decided, we are keen to keen the squares ticking over either at home, portable or mobile :) Ian & Esther. :lol: