My activities on 1 GHz and up
(non - ATV)

* 1 - 5GHz Narrow Band Activities
* 10GHz NB and WB Activities
* Go here for my 24GHz NB Beginnings
* Go here for my 38GHz Commercial Xceiver

Over recent years I have been building up a collection of microwave equip. from 1 - 38 GHz, some of it commercial and some
homebrew. The idea being to have a lot of different designs to choose from when wanting to construct a working system. E-bay
has been a good source of ex commercial NEC and Harris 5, 24 and 38 gig xceivers. Amateur radio club trash and treasure
sales have also been a good source of parts like - Satellite LNC's etc that are reasonably easy to convert from their 12-14 gig
to 10 gig to be used as low noise pre-amplifiers.


1296MHz activities
The 8th Sept.'07 was my first decent test on 1296MHz. It came as part of a weekend of microwave ATV activities inland
from Sydney, between Mt Towac (near Mt Canobolas, Orange) and Mt Ginini, near Canberra. This was a distance of
241km a personal best for me, outstripping my previous best of 76km on a path along the NSW coast between Dobroyd
Pnt and Wybung Head. I was using a varactor tripler from my 432MHz transmitter to produce approx. 6W on 1296MHz.
This was fed to my 21 ele. yagi. For receive I was using an AOR2002 scanner on loan.

There were 2 sets of contacts for the day, firstly --- to Dave, VK2JDS who was NE of Orange and 40km from our location.
Signals were ludicrously strong, 9+40 both ways. Dave was running ~ 20W into a 3m dish, and we could still hear his signal
at 9+ even with no antenna in the AOR receiver.
The second path was to Bob, VK2MRP/P1 who was on Mt Ginini near Canberra, a 241km path. Signals both ways were
9+10-20 making it a very easy contact and leading me to realise that much greater distances on FM were possible ... looking
forward to breaking the 500km barrier.


Above -- 1296MHz Yagi -- The boom is just on 2m long


Above 1296MHz Tripler photo; and to the right, click on thumb for cct diag. of tripler

A few brief comments about varactor triplers .... 1) -- FM only; 2) --- They are around 50% efficient, ie. 10W in ~ 5W out.
The BAY96 Varactor diode ( a popular one) can handle ~ 15-18W at 432MHz max. I personally wouldnt risk pushing it
harder, the diodes are getting very hard to come by. 3) --- Don't forget, not only is your freq tripled, so is your FM
deviation, only a quiet voice, almost a whisper is needed into the 70cm TX microphone.

Here's a couple of 1296 antenna ideas that I have played with in the past. The dipole was designed for use with a corner
reflector. I based this scaled version on a design for 1500MHz and found that it worked well on 1296MHz.





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Page created 26 Jan 2005
Modified 08 July 2008 (removed 10GHz into to its own page)
Dave VK2TDN