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A frustrating morning


#1

My Sunday morning jaunt was not primarily intended to be a SOTA trip. The main intention was to give my FT-847 a rare airing in the RSGB 70MHz Trophy contest. With the additional weight, and the bigger battery, it made sense to choose a location where I could drive to the top, so I chose Botley Hill (G/SE-005) - a quick half-hour journey along the M23 and M25.

Having arrived and parked on the wide grass verge along the B269, I carried the gear a few yards and set up. Bearing in mind that I only have a whip antenna for 4m, I was not expecting fabulous results, but, with a clear view across London to the north, I felt confident of making a few QSOs.

As I switched on, I was surprised not to hear any signals at all! I checked all the connections and rig settings, and everything appeared OK. Transmit indications were normal, but nothing could be heard except background noise and occasional ignition noise from passing traffic.

I was beginning to believe that I had got the contest date or time wrong when, after ten minutes of increasingly desperate tuning around, I eventually heard a signal! There was G0VHF/P, somewhere near Southend-on-Sea, but painfully weak. Normally, wherever I am, they are an end-stopping signal. No point in calling as they would never hear me.

Having admitted defeat on VHF, I decided to try a more familiar 40m CW. The antenna was quickly erected, and the band was full of big signals. Luckily for a Sunday morning, I found 7032.5 unoccupied. A quick CQ SOTA produced a monumental pile-up – delicious! I started to work through the heap of callers, but, after half-a-dozen QSOs, the rig started to misbehave. The symptoms looked like a low battery, so I tried my usual trick of reducing output power. Still the problem persisted, even with power down to about five watts. With just seven stations in the log, I admitted defeat once again.

Now back at home, the battery seems OK. So I must investigate further as to the cause of the problem. My apologies to those many stations still calling as I switched off. I will return to SE-005 with a fully-functioning rig sometime soon!

73 de Les, G3VQO


#2

In reply to G3VQO:

I think you should check that 4m equipment again Les because my experience yesterday was the complete opposite to yours!

I went up Moel y Gamelin, NW-042 specifically to take part in the contest.
I was a little late setting up but when I switched on at 0915 the band was buzzing with signals and it was difficult to find a clear frequency.
By 1000 I had 15 contacts in the log and by the end of the contest 65, including five GM,two GU, one GD and best of all a brief Es opening providing three 9A and two OK contacts. I also worked G0VHF/P at good signal strength!

So save that whip for FM contacts Les and get yourself something horizontaly polarised for the next contest (14th Sept) and have some fun!

Ron.


#3

Curiouser and curiouser!

Since returning home I have thoroughly checked all parts of the equipment used on Sunday morning.

As expected, the battery was almost fully-charged, and was more than capable of running the FT-847 at 100 watts. The rig itself seems to be performing normally, both on receive and transmit. I even heard a semi-local station on 4m with the same whip antenna from my garage!

Nevertheless, I have given all of the various connectors a good cleaning just in case the was a dodgy connection somewhere. I just hope that everything will perform normally next time I’m out portable …

73 de Les, G3VQO


#4

In reply to G3VQO:

Hi, Les.

A possible explanation. How about two separate problems - one provoked by the other?

The FT847 is very deaf on 4m RX. It was never intended for use on the band and I suspect Mr Yaesu is horrified that we use them unmodified on 4m. Have you ever looked at the output spectrum? I use a MM PA / Preamp in front of mine to combat the deafness and give a bit of filtering on TX. Combine that deafness with the use of the whip antenna and that could explain the lack of signals heard.

The other characteristic of running on 4m is that the rig gets very hot. After a period of running on 4m maybe the temperature was close to causing the PA to shut down (I can’t recall if there is thermal protection). Swapping to HF might just have tipped it over the edge - especially if there was any sun on the rig (difficult to believe in this wonderful summer of ours).

Maybe clutching at straws but it would explain the lack of a fault found back at home with it all cooled down again.

73, Richard