Thanks for stopping by. This is where I publish a lot of my features and thoughts on HF propagation, antennas and other ham radio topics. I write for a number of radio magazines, including the RSGB's RadCom and ARRL's QST. I am also chairman of the RSGB's Propagation Studies Committee and produce the weekly HF propagation report for GB2RS. When not playing radio I'm a professional journalist specialising in aerospace, science and technology and am also author of four RSGB books.
Friday, 23 October 2009
Snowdonia Radio Company SRC X65 65ft end fed
I bought one of these at a local rally. It is a 65ft wire and a 9:1 UN-UN. The guy who sells them is very friendly and is an ex Royal Signals op (I think). At only £30 it is barely worth making your own. I set it up as an inverted L with a 10m fishing pole. So it was about 9m up and about 10m sloping down to my shed, tied off with fishing line so that the end was about eight feet off the floor. I used a single ground stake and six 20ft radials.
Here are the results:
SWR measured with MFJ 269 at end of 30ft of coax.
Single earth stake and six 20ft radials
3.5MHz – SWR 3.5:1
3.6MHz – SWR 4.4:1
3.8MHZ – SWR 6.2:1
7.10MHz - SWR 4.8
10.1MHz – SWR 2.6:1
14.2MHz – SWR 2:1
18.14MHz – SWR 1.7:1
21.2MHz – SWR 1.9:1
24.9MHz – SWR 1.7:1
28.5MHz – SWR 1.3:1
29.6MHz – SWR 1.9:1
50.1MHz – SWR 1.9
On–air comparison with 135ft Windom (OCF)
80m
Similar signal strengths to Windom around UK, sometimes 2-4 S pts down, but 1-2 S pts. less noise. Holland down 2 S points. Germany 1 S pt better.
40m
Similar to Windom on PA and DL, F similar, IK similar, G similar.
20m
UA 1 S pt better on SRC, IK better by 1 S pt, YO similar
17m
Similar – inverted L has slight edge at times. Slightly quieter
15m
Better than Windom by about 1 S point, sometimes better, sometimes worse.
12m
All signals better by 1-2 S points
10m
Much better than Windom, dipole and mag loop, by about 2 S points. UA three S pts better. Slightly noisier. 5B4 beacon 2 S pts better.
I was very surprised at how good it was on 10m – or my Windom is very bad. I think this could be a keeper. See http://www.snowdonia-radio-company.co.uk/
Update: In the CQWW SSB contest on 24/25 October I worked more than 20 countries using the antenna on 10m, including ZS9 - very good!
I heard someone talking about an UN-UN from Snowdonia Radio on an HF net several days ago. I thought I had better have a look, and then promptly forgot. I am glad I am saw your blog! Looks very promising.
ReplyDeleteVery nice blog on ham radio. Useful information are provided in this blog.
ReplyDeleteSteve do you think it would be any good to just use this an a random wire from my 2nd storey bedroom to the summerhouse in the back garden? This would be my first ham antenna, just something to get listening and my first QSO. All the best,
ReplyDeleteScott M6OZI scottnjill204@btinternet.com
This is a great antenna had contact whith 27 countrys so for with my src x65 antenna
ReplyDeleteShame SRC had to close, my local club had good connections with Simon and were all saddened when SRC finished in 2012.
ReplyDeleteThe G-whip 'wide-bander' is similar. 22m wire + 9:1 UnUn, and a 20m counterpoise. I use it for a holiday aerial & usually just zig-zag the counterpoise around the patio. G3ZPF
ReplyDelete