Sunday, 12 June 2011

80m Field Vertical

Im going to get cracking with this. I have a 10m fibreglass telescopic pole (a windjammer), for which i have already worked out a neat guying system using bungy cords, and have created a radial plate for it.

The proposed design is a top-center loaded vertical. The coil will be positioned 8 ft from the top, allowing that bit extra wire for capacity. Calculations show this should be about 55% efficient. Combined with my MKARS-80 giving 3-5w, this should let me have an erp of about 2w. Not great, but the real benefit is expedience - i can get this rigged at a portable site/summit in about 5mins

Im also considering a linear loaded coil vertical. But winding the coil every time i put the pole up would be slow, tedious and inaccurate. I wonder what a slinky streched over 30ft will resonate at???

Saturday, 11 June 2011

QRV 6m

Well, ive not updated this for, ooh, i dunno, ages. Other things have taken the time.

Anyway. I now have the doublet back up, and its working ok. Its not perfect, but its working sufficient to make contacts, including some nicely impressive DX. Yesterday, on 17m, i worked Cuba with just 10w, for example.

The 3 element yagi for 6m is up, albeit on the 'test' mast, at about 15ft. 6m is very good at the moment, plenty of sporadic E to work.

The one thing that has struck me about working SSB on 6m, is the business-like operating. No messing about, reports and locators, and then clear, but at the same time not overly rushed. Very pleasurable short QSO's.

Im still considering the best way of securing the main mast to the side of the house, im not at all happy with expansion bolts into engineering brick, i just dont think they will hold well enough if they penetrate one of the voids. Im wondering about using a steel backplate and M10 threaded rod right through the wall for the top bracket, which will take the worst of the wind loading. The pole i have is steel, so its heavy. Maybe i should bite the bullet and get an aluminium pole ordered!

Julie is not particularly keen on the 6m yagi, so would be even less happy with the 9 element 2m Tonna. But if they were up at 30ft, perspective means they look smaller. They will also perform better!