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LOOP AERIAL OR?
https://hamradiodeals.co.uk/forums/viewtopic.php?f=43&t=49204		 Page 1 of 1
Author:  g1elg [ Thu Nov 07, 2013 10:13 am ]
Post subject:  LOOP AERIAL OR?
Hi all.I now live in a high rise sheltered housing block.Only space for aerials is the balcony.Nothing is allowed to project from this.I have a "window"of 3mX1.5m,would something like this work? http://www.southgatearc.org/articles/g0 ... tennas.htm Meant to say the "window"is protected by pigeon netting so handy for threading wire through.I have a g whip sealed balun with no markings,how do i check what ratio it is?Atm/atu available are mfj 949e,ldg at100pro and z100 plus.All ideas for HF 40m to 10m thankfully received.Thanks.stu.
Author:  G3TXQ [ Thu Nov 07, 2013 10:28 am ]
Post subject:  Re: LOOP AERIAL OR?
That will work, but keep the balun and tuner as close to the loop feedpoint as you can. Also, the bigger you can make the loop the more efficient it will be. On the lower frequency bands it would help efficiency if you made it of "fat" wire - you could use RG174 coax as the wire, or even RG58.

To check the balun ratio, connect a 50Ohm load to the antenna side of the balun and check the SWR at the input - use low power. A low SWR indicates a 1:1 balun and a SWR around 4:1 indicates a 4:1 balun.

73,
Steve G3TXQ
Author:  g1elg [ Thu Nov 07, 2013 12:13 pm ]
Post subject:  Re: LOOP AERIAL OR?
Just checked the balun,it would seem to be 1.1.If i use rg58 for the wire,will i just use the braid,or.does it need stripping?Will any of the listed atu suffice.Thanks for your help.stu.
Author:  G3TXQ [ Thu Nov 07, 2013 1:17 pm ]
Post subject:  Re: LOOP AERIAL OR?
If you use coax, there's no need to strip the jacket. Just connect to the braid as if it were a piece of wire; you can leave the inner conductor disconnected, or connect it to the braid - it makes no difference.

I would expect the MFJ manual tuner to have the widest matching range and best efficiency.

Steve G3TXQ
Author:  m0jha [ Thu Nov 07, 2013 6:01 pm ]
Post subject:  Re: LOOP AERIAL OR?
I have used a loop using sticky back copper trip off a roll that I stuck around the window with the two ends running down towards the floor behind the curtain . It is roughly 22 foot all in ( 8x3 window frame) with about 3 foot to the floor .. tuned 40 using a 945 atu and a couple of watts but didn't try other bands as it was on a monobander , worked EU with apparent ease ..

I havn't used it tx for a while as I thought maybe I was getting a little obsessed "needing" to run a radio in bed :) but use it now and again to hook the TECSUN rx but to be honest the antenna on the rx works well as it is for casual listening ..

could you not drop a random wire over the balcony at night and load it against the balcony itself ? maybe worth a try , I have done ok in the past with a wire slung out the kitchen window to the bushes 20 odd foot away no higher than 5 foot with a counterpoise to the sink ..
Author:  G6CSL [ Thu Nov 07, 2013 6:29 pm ]
Post subject:  Re: LOOP AERIAL OR?
''I have done ok in the past with a wire slung out the kitchen window to the bushes 20 odd foot away no higher than 5 foot with a counterpoise to the sink ..''

Funny you should say that. I'm still using that setup here in my kitchen until I get my 'man shed' together.

It's amazing what I can hear. Especially high-angle NVIS stuff on 60m and 40m. Real ''Allo allo this ees nighthawk'' stuff.

How about a big black spiderpole shoved out horizontally after dark? If you're on one of the higher floors, you might be amazed :)
Author:  g1elg [ Thu Nov 07, 2013 9:35 pm ]
Post subject:  Re: LOOP AERIAL OR?
Thanks everyone for your help and suggestions.Tried dangly wire loaded against balcony before this block was refurbished,at a cost of £5 million.All residents have been warned,no aerials of any description and no drilling holes etc.Regards.stu.
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