02-06-2023, 04:19 PM
Co. Clare in Ireland had 625 Line on Band I from 1962 till 1999 and I believe there was interference from Norway once.
This week I was testing a 3 m whip for 70MHz and after VNA tests went on air. As expected it couldn't be used to transmit on 50MHz ( too close to a half wave for the FC40 tuner which is bypassed on 70Mhz). However a Western Sahara Amateur station (approx 50.15x I think) was busy with UK stations that I couldn't make out. He was 5 & 3, very clear (SSB). I also heard a Norwegian that day. So obviously North/South propagation. The aerial was on a "workmate" type bench clamping a 1.5m pole as a mount and only about 2m from the gable end of the house near the middle.
After twenty years of an FT101ZD as main station rig I splashed out on an FTdx10 last September, but not used it much yet. The approximately 3/4λ whip (306 cm) with 3off 1m radials deliberately has no matching at the base so it can be used as an HF vertical on the FC40 remote "tuner". A transformer match for 6m (50MHz) works, but then 70Mhz and HF doesn't work. Putting an exact lenght (possibly 1/4λ?) coax between the whip and the tuner makes 50MHz sort of work (likely about 700V RF at whip base at 100W on 50 MHz) . It works OK for 3.5MHz. The 1.8MHz would need a bigger base loading coil than most ATUs provide. Maybe the answer is remote relay switches when it's put on the chimney. Contact rating would be challenging.
This week I was testing a 3 m whip for 70MHz and after VNA tests went on air. As expected it couldn't be used to transmit on 50MHz ( too close to a half wave for the FC40 tuner which is bypassed on 70Mhz). However a Western Sahara Amateur station (approx 50.15x I think) was busy with UK stations that I couldn't make out. He was 5 & 3, very clear (SSB). I also heard a Norwegian that day. So obviously North/South propagation. The aerial was on a "workmate" type bench clamping a 1.5m pole as a mount and only about 2m from the gable end of the house near the middle.
After twenty years of an FT101ZD as main station rig I splashed out on an FTdx10 last September, but not used it much yet. The approximately 3/4λ whip (306 cm) with 3off 1m radials deliberately has no matching at the base so it can be used as an HF vertical on the FC40 remote "tuner". A transformer match for 6m (50MHz) works, but then 70Mhz and HF doesn't work. Putting an exact lenght (possibly 1/4λ?) coax between the whip and the tuner makes 50MHz sort of work (likely about 700V RF at whip base at 100W on 50 MHz) . It works OK for 3.5MHz. The 1.8MHz would need a bigger base loading coil than most ATUs provide. Maybe the answer is remote relay switches when it's put on the chimney. Contact rating would be challenging.
