Thursday 7 May 2015

Going Helical

I'm one of those people that can either get big things done in no time, or small things done not at all.

Setting up a proper station on VHF and UHF is one of the latter cases, where I've been messing about with handhelds and wire-and-stick antennas for years. 

A similar antenna is on its way...

Part of my failure to move ahead has been the remarkable success obtained with the cheap-and-cheerful handhelds from China, especially on satellite working - restricted solely to SO-50.

So, having ventured to use repeaters on the Isle of Man at 70cm, I've now set upon developing the V/UHF side of things for good.

Of course, it's quite an expensive business to get a multimode V/UHF rig.  I'm looking at the FT 857D, which comes in at about £650.  A twin-axis rotator is the same.  Antennas add about £250 to the mix, and low-loss coax is certainly not an insignificant factor.

Now, don't get disheartened; you don't need any of the expensive stuff to work satellites.  I've done it for years with no m ore than 5W from a 5-ele homebrew quad (uplink) and 7-ele quad (downlink), the 2m antenna perched on a simple pole that was turned by hand, and the 70cm one held in the other hand.

But, as I am interested in digital modes, multimode is needed here. 

I was quite lucky to come across a web site by a J.R, Miller, who had one helical antenna for 70cm left for sale.  It seems it was some kind of project at one time, perhaps faded away rather by now.

Being over 3m long, there was no question that an antenna that large was overkill in gain for sat working.  It would also likely suffer in the heavy winds up here, even at fairly close to ground level.  Mr. Miller offered to sell me, in effect, a cut-in-half version, only 1.6m long.

So, having bagged myself a nice antenna for 70cm, it's time to assign funds sensibly to the next stage - which appears to be the acquisition of a Yaesu G5500 rotator.  Sadly, I am not very good at electronics such that I could make my own motor!


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