* LA7DFA *            JX7DFA SHORTWAVE            * JX7DFA *
JX3P & JX7DFA 1989, Photo: JX7DFA
In April 1989 I went to Jan Mayen for the first time to work at Jan Mayen Radio & Loran-C station. Back then we did not have satellite communications, so all telephone and telex traffic relied on the communications we could make on MF/HF. Since 1989 was close to the solar maximum, we had frequent radio blackouts. I recall we had 10 days in a row with nearly no communications on any frequency including 433KHz! I made nearly 20.000 HF contacts from April till October 1989. JX7DFA, Photo: Kenneth Jonas

Due to high mountains, I have to use sidescatter on 28MHz to USA. Sometimes I did notice very raw auroral sound on 28MHz signals from North-America from this QTH.
During the summer we have frequent Auroral-E openings to N-Europe. The propagations usually peaks at 2130 UTC. The signals are often best on 28MHz and gradually reduce in strenght when frequency decreases (down to about 10MHz). The A-e propagation often extends to 50MHz and sometimes 100MHz. I have made contacts on 144MHz and heard signals on 169.900MHz (the highest VHF frequency used at Jan Mayen).

Photo: JX7DFA

On 160, 80 and 40M we have local QRM from the 250KW Loran-C transmitter. It is only 800M away and produces harmonics over the lower part of the MF/HF spectrum. It sounds like a 'fast woodpecker' and you need a good noiseblanker to reduce the noise. (Plus some staying power:) The propagations are very difficult from 71N on the low bands. It can be quite frustrating to make DX skeds on 160M or 80M, due to hopeless propagations 29 of 30 days...
  
Jan Mayen island during spring, Photo Knut Boeckman

DIGITAL MODES

PACTOR I, II & III

PACTOR is a fast and reliable ARQ teletype mode. Developed to overcome the shortcuts of AMTOR and Packet Radio on short wave. From Jan Mayen this is vital improvements, epecially during the frequent auroral disturbances. PACTOR-III is up to 5 times faster than PACTOR-II. As JX7DFA I was standby on 10.137.9 FSK most of the time. My system did autocall every hour and mostly used highspeed Pactor-III. Winlink2000 and its client - Airmail were exellent tools for obtaining my e-mails. This was the only way to get my e-mails on the island before 2001!

The PTC-II modem was also used for other digital modes like SSTV, RTTY and PSK31.
Some years ago I used mostly Packet to access the mainland, but it was quite difficult to get any datas when conditions were average or poor.

Tikkebu, photo JX7DFA
   
SSTV received by JX7DFA
SSTV received by ON7GB
SSTV received by JX7DFA

SSTV received by ON7GB
MODES USED BY JX7DFA ANTENNAS USED BY JX7DFA
CW, SSB, FM, SSTV, PSK31, RTTY 160-30M Conical vertical with 100 radials + 85M Deltaloop
PACTOR I, II, III, PACKET & GTOR 17 & 12M 85M Deltaloop
  10-15-20M 3 ele yagi (FB33) + 5 ele 10M monobander
  6M 6 ele yagi
  2M 4x14 ele M2 longyagis + 4x15 QueDee yagis


(Photos and animation by Per-Einar Dahlen)