09-03-2024, 08:40 AM
Sometimes you just wonder why.
After a hiatus caused initially by the NBN, the interruptions of Covid, moving interstate, making the new house liveable, learning to enjoy the new surroundings, coping with an awful project at work (you know, life stuff) I have dusted off some of the gear and started cobbling a temporary (for now) station together.
Our block has a largish veggie garden that has a metal frame over it with a shade cloth cover. Methinks that as an interim solution to overcome the analysis paralysis of what real antenna/s to put up, I will bung a bit of angle onto the frame, whack on a delrin base and stick my FAMPARC multi-tap helical whip and run some coax across the yard to it.
As I wasn't too fussed and the VSWR was within reasonable limits that the tuner could handle - I looked no further.
I got the radio and interfaces up and running. Lo and behold I was getting decodes on FT8 immediately. I spent a couple of evenings trying the break the duck on my VK5 callsign.
No luck. Plenty of decodes and PSKInfo said I was being heard and decoded all over the place.
Early this morning, about an hour before the sun it was over 25°C so I got up and started mucking around on 20m FT8 again. "Hang the expense, I'll do a quick tune of the helical" I said to no one in particular.
Broke out the VK5JST analyser, yup it still works so off I go to tune this thing. Back and forth, up and down the ladder, you know the drill. From one end of the adjustment to the other. Best I could do was 2.63:1.
Seems odd to me.
Once the sun had risen and I could see more clearly I decided further investigate the groundplane/veggie garden sun shade. It is all 40x20mm gal section in a grid, held up by treated pine posts. I grabbed a DMM and started to check continuity amongst the frame members.
Mostly good. Except the cross member I had chosen to attached to. It must have been an afterthought, added for bracing. It is screwed to the pine uprights, but air gapped where it passes the other metalwork. To quote Adam Savage from Mythbusters "There's your problem". The groundplane was a single 40x20mm gal section about 3 metres long.
Back to the drawing board, I guess.
After a hiatus caused initially by the NBN, the interruptions of Covid, moving interstate, making the new house liveable, learning to enjoy the new surroundings, coping with an awful project at work (you know, life stuff) I have dusted off some of the gear and started cobbling a temporary (for now) station together.
Our block has a largish veggie garden that has a metal frame over it with a shade cloth cover. Methinks that as an interim solution to overcome the analysis paralysis of what real antenna/s to put up, I will bung a bit of angle onto the frame, whack on a delrin base and stick my FAMPARC multi-tap helical whip and run some coax across the yard to it.
As I wasn't too fussed and the VSWR was within reasonable limits that the tuner could handle - I looked no further.
I got the radio and interfaces up and running. Lo and behold I was getting decodes on FT8 immediately. I spent a couple of evenings trying the break the duck on my VK5 callsign.
No luck. Plenty of decodes and PSKInfo said I was being heard and decoded all over the place.
Early this morning, about an hour before the sun it was over 25°C so I got up and started mucking around on 20m FT8 again. "Hang the expense, I'll do a quick tune of the helical" I said to no one in particular.
Broke out the VK5JST analyser, yup it still works so off I go to tune this thing. Back and forth, up and down the ladder, you know the drill. From one end of the adjustment to the other. Best I could do was 2.63:1.
Seems odd to me.
Once the sun had risen and I could see more clearly I decided further investigate the groundplane/veggie garden sun shade. It is all 40x20mm gal section in a grid, held up by treated pine posts. I grabbed a DMM and started to check continuity amongst the frame members.
Mostly good. Except the cross member I had chosen to attached to. It must have been an afterthought, added for bracing. It is screwed to the pine uprights, but air gapped where it passes the other metalwork. To quote Adam Savage from Mythbusters "There's your problem". The groundplane was a single 40x20mm gal section about 3 metres long.
Back to the drawing board, I guess.
Colin
Barossa Valley, SAP. PF95ln
(aka VK5CSW)
Barossa Valley, SAP. PF95ln
(aka VK5CSW)