Loft antennas

Suggestions for and practical usage of antennas

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Loft antennas

Postby mikeadams » Sat Nov 23, 2013 10:32 pm

Tried a 2m vertical in the loft with reasonable results using a rather deaf IC706. Changed it today for a turnstile antenna that I have used for WX reception. Now clearly this antenna is constructed for around 134Mhz - - very disappointing results tonight but not sure if the signal has been reduced to 30mW. May try the 2m vertical again tomorrow. What antennas are others using? 73 Mike G0AMO
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Re: Loft antennas

Postby g4dpz » Sat Nov 23, 2013 11:12 pm

Hi,

At the LEOPS ground station we tried turnstile and quadrifilliar omni directional antennas. The quadrifilliar was much better.

The quad was home-brew and the TS commercial.

- Dave
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Re: Loft antennas

Postby G0KYA » Mon Nov 25, 2013 10:44 am

I have a 2m Slim Jim in the loft fed with about 12m of RG58 coax. This is far from ideal, but the cabling was put in when I first moved in for HF - I have three such cables that go out of the shack wall, up the front of the house and into the loft. It isn't too ugly, but RG213 would have been far uglier and I have the "station manager" to consider!

The Slim Jim combination usually gives an S2-3 signal on a 20-40 degree passes using an Icom IC-7400 with the pre amp on - it hit S4 this morning. I don't think this is ideal, but it gets you going and when the signal strength comes up it gives 75-100% packet decode success.

For two-way comms when the satellite is in shadow and running low power I think a beam is going to be much better. I have a two element Moxon for 2m that I can set up just outside the house with a short length of coax. I'll report back if it is better.

Steve G0KYA
Wymondham. Norfolk

PS I note that the spacecraft is appearing a little later than the Keps I was using predict. I have just upgraded them to:

Funcube
1 39417U 13066B 13328.52822701 .00004709 00000-0 65186-3 0 152
2 39417 97.7995 41.0710 0063010 185.6906 174.3718 14.77115537 473

and it seems a little more accurate. Where the Keps not quite right or are we seeing the effects of drag?
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Re: Loft antennas

Postby mikeadams » Sat Nov 30, 2013 11:51 pm

Set up a 4 element beam on a rotator in the loft today. Fixed at 30 degrees up from horizontal. Despite a rather deaf IC706 this seems to be working well with a reasonable collection of data today. Last pass was way out west but managed to decode a few bursts of telemetry adding a few more to my counts total. Currently 273. Will experiment further over the next few days - waiting to order a FunCube dongle when they are available. 73 all de Mike G0AMO
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