MØMCX

Amateur Radio Operator


Dave Barber (G8OQW), what are you on OM?

Tonight, I made a post about a real-world test I did for 70 cms two weeks ago, just before my Group Scout Camp since I had a choice to make a 25 meter extension lead out of Westflex or EcoFlex 15 for a walkie-talkie system based on 70cms that I promised to run for my Foundation candidates. I ran both coax types up the tower and tested them out individually on 70 cms with a local station (sub-20 miles) on both 145MHz and 433MHz. The results showed a dramatic difference between the Westflex above 2 meters. Essentially, my test demonstrated that fall-off with the Westflex was dramatic as the frequency became higher. In response to a query on Westflex to the UK Contest reflector, I posted an answer explaining my findings that EcoFlex out-performed Westflex by a large margin.

His reply is as follows:

Hi Callum

That is an astonishing difference!

For the figures quoted @ 432MHZ

25m WE103 = loss 1.88dB

30m Eco15 = loss 1.83dB

So a theoretical feeder difference in your setup of 0.05dB.

Now as an owner of a TS2000 I know the S-Meter on FM is a farce but for a moment lets take it as being correct and an S point = 6dB increase so your 6 S point increase would indicate a signal level difference of 36dB at the radio.

That really stretches the imagination and if correct you should easily become a multi millionaire overnight! 

David, I’m not sure how I am to make my money, perhaps you can send me cheques for my experiments?

Callum.

July 1st, 2008 Posted by admin | Amateur Radio | no comments

17 Element Tonna Test for 2008 VHF NFD

17 Element TonnaOur 17 element Tonna is up for a test tonight, to ensure that everything will be working for VHF NFD event this weekend. Initial results are proving that its an extremely capable antenna and at 30 feet high, it’s just sitting over the rooftops, giving me a clear run across Warwickshire to the continent.

Fingers crossed for a bit of a lift tonight since it’s the 2m activity contest and James is popping over for some practice. I’ll write up a small report later.

More photos: http://www.m0mcx.co.uk/gallery/index.php?/category/73

In case you are wondering, yes that’s a Yaesu rotator bearing that I’m guying to at the 9.5 meter mark. It’s not holding the mast up, just taking the horizontal strain off the rotator.

[Later]

41 QSOs in tonight’s contest and 12 square multipliers. Not a big score but jolly good fun and at least we seemed to be ini the top third in terms of score. Longest DX was GM3UCI for 398 Km.

Callum.

July 1st, 2008 Posted by admin | Amateur Radio | 2 comments