- Thursday 27 and Saturday 29 April
- Part of my holiday was spent making another attempt to get a
signal out of west Wales on the 73kHz band. I am the only person
to have transmitted from GW on this band. Although my own holiday
home is less then 0.5km away I cannot operate from there because
of adjacent high voltage wires. I have to operate from a generator
as my 73kHz amplifier runs from 230V. The noise level on 73kHz
was high as the Rugby transmitter had been switched back on again.
- My original plan was to operate on Wednesday, the 26th, but
the weather forecast was for rain in Wales and storms in south-east
England. Decided to postpone for a day.
- On Thursday, I operated from a car park very close to
the beach at Freshwater East, near Pembroke. I have used this
location (IO71NP) successfully before on the 136kHz band,
working into SM at over 1400km using 200W to a 60m vertical on
a kite. This was the set-up I used for the 73kHz tests.
- Tested the kite at 1500UTC and it flew well at about 30 degrees
from vertical in a gentle breeze. Started to set up the Tx an
hour later for a sked with G3LDO at 1700UTC. Kite was a little
lower at 45 degrees but still OK. Spent the next hour getting
the earth wires out and the Tx running (anyone who has ever operated
a radio in the field will tell you that if anything can go wrong
it will go wrong - and it did). Finally got 2A into the antenna,
which is twice what I get at home. Maximum current was at the
top of the band, so I added more inductance, then noticed that
the current was varying wildy. The cause? The wind was reducing
and I could see the kite dropping very slowly and the lower part
of the wire was sparking to some gorse bushes.
- The only thing I could do was to reduce the height of the kite
as there was less wire to support, and finally I had about 30m
of wire at 45 degrees with 1.5A current. The coil of spare wire
was put carefully in the car boot on a blanket. Investigating
a funny smell led me to find the blanket on fire from the sparks
off the antenna!
- Phoned G3LDO to tell him I was now ready and he listened but
heard nothing. He transmitted to me and I could not hear him either.
Finally packed up after two hours of operation, rather disappointed.
Kite enthusiasts had told me that the wind tended to drop during
the evenings (and at dawn), and this was a very good example.
- Another session was scheduled for Saturday morning, but
would have to be short as the hired generator had to be returned
by 1100UTC - or I had to stay in GW another two days! The good
news, however, was that I had heard from MI0AYZ that he and GI3PDN
would operate from a Decca mast in GI. I knew that this would
be almost completely a sea path and that this was a great opportunity
for a 'first'. A sked was made.
- Got up at 0530UTC and checked out the wind - there was none
at all! At the Freshwater location, the kite failed to move off
the ground. No problem, I had a Plan B - a cliff-top site about
20 minutes away to the west at Broad
Haven (note that I could not operate from just anywhere as
the rules of the 73kHz Notice of Variation insist I notify the
authorities of exactly where I will operate when away from home.
With some foresight I had listed three locations). But there was
no wind at Broad Haven either. Plan C involved the
Prescelly mountains (450m+ and about an hour away). It was
at this time that I regretted failing to collect my 16m portable
mast from M0BMU who was looking after it after the Puckeridge
trip.
- Having concentrated on the radio side of the trip, I had omited
to check my fuel levels and had a rather worrying journey of four
miles with the fuel warning light on, expecting to run out at
any time. Fortunately, I reached a garage in time.
- Arrived about half an hour before my sked with MI0AYZ. Tried
the kite - surely there would be enough wind at 600m ASL. There
wasn't. Always resourceful - as all true radio amateurs are -
I ran a 100m wire up a very steep hillside using fence posts as
supports and bits of perspex (ex Puckeridge Decca) as insulators.
A similar length of wire formed the counterpoise running down
the hill. I had used a very much poorer antenna at this location
with much less power to set the existing GW crossband distance
record of 32km two years ago. Once tuned up I had 1A into the
antenna and the received signals were as strong on the meter as
they are at home, and with very much lower noise. I could hear
MI0AYZ at a good 579, but could hear nothing of the Gs he was
working.
- Phoned GI3PDN's mobile and told him I was ready. For half an
hour we called each other but with no success at all - he could
hear nothing from me. I even tried again to fly the kite but it
was not stable. By now I had run out of time and when called on
the phone by G3YXM I had to refuse a sked!
- I finally got the generator back to the hire shop with 15 minutes
to spare, and resolved to come back again in a few weeks.
- My kite will fly with a wind of 10kph+ so there's a good chance
of success next time.
More
about Freshwater East beach
More
about the Prescelly Mountains |
