23cm on two Watts and a prayer

A few month back one of the members of my radio club posted to the clubs group.io group that he had participated in the April 23cm UKAC using a his new IC9700 and a tri-band vertical and managed three OSO's.    

His foray into the world of 23cm's had me dusting off my SG-Labs 23cm transverter I had bought a few years previous and had sat on the shelf and actually give it a whirl. 

The transverter is the MKII version and has a power output of 2.5W so real QRP compared to the IC9700's 10W.  The only antenna I had was a similar tri-band (Comet GP-95N) with a gain of 12.8dBi if you believe that?  The feeder was 15m of Ecoflex 10 so feed losses were going to be around 2.47dB.   So all things considered ERP would be around 16.5W.    

Using an FT817 with the above setup I entered my first 23cm UKAC and was amazed to work 7 stations with the best DX being G3MEH at 105km.  

I can't remember now if I used the ON4KST microwave chat during the first contest but I believe I didn't but with all subsequent contests I did.  

Anyway I was actually amazed I did so well with such low power and polarisation mismatch but that one contest had given me the incentive to do the next contest.

For the June contest I made the easiest change I could and bought an 18 element Yagi a  PA1296-18-1.5RB from Antenna Amplifier in Serbia.  The antenna gives a reported gain of 17.16dBi this of course gave me an increase in ERP from 16.5W to 45W which should give me improvement of around half an S-point and of course the 30dB improvement from having no polarisation mismatch. 

You can see from the table below there has been a steady improvement in points and DX though in August there was some great tropo as shown by the fact I worked OZ1FF on 2W though it was mainly sea path but neither the less I was extremely happy.

Month	QSO's	Points	DX Km
May	7	1877	105
June	11	2154	105
July	11	3070	180
August	11	3624	208
September	19	8357	670

So the next easy upgrade will be replacing the current feed cable with Ultraflex 13 but that will only yield another dB but it will be in place for the October contest.   

Next up will be finishing off the 80W amplifier I'm building and sticking it in a box.     The finished unit will have a LPF by John G3XDY, a 80W PA based up John G4BAO well known design with a homebrew controller to switch the pa and tvrx while also displaying output power, temp and VSWR.