[VHFcontesting] 222 MHz amplifier

[David Olean]

I am in the middle of getting the last 500 watt amplifier running on 222 
MHz. This one is a special one that includes pre drivers so it can be 
run directly from a very low power transverter. After finishing up the 
wiring I put some RF through it and about 0 dBm puts out 100 watts or 
so. +8 dBm nets you +57 dBm or 500 watts. I did not play with the fan 
settings but saw very low heat rise with the heat sink. (Which is 
massive) I have two 24 VDC fans running to cool the heat sink. I gave up 
trying make it too hot. It runs cool no matter what.

The plan is to add the W1GHZ transverter kit on the additional heat sink 
space so that you end up with a 500 watt transverter fed with 48-50 VDC 
and some 28 MHz RF.  I have all the parts for the x verter, and just 
need to order a better solder work station for surface mount parts. I 
need all the help I can get making the ckt board assembly due to a very 
shaky right hand. When the transverter is finished it will be phase 
locked at 222 MHz and include a GPS antenna for maintaining long term 
accuracy.

This will make a great station for 222 MHz, and while it is not QRO 
enough for EME (unless you are WA4NJP with a huge dish!!)  it will be 
great for meteors and aurora and tropo. 500 watts is  a pretty good 
level.  So I am looking for people in rare VHF spots who might want such 
an item. Everyone wishes there were more stations available south of the 
Wash DC area. So anyone in N or S. Carolina, Georgia, Alabama etc. would 
be a prime candidate. This goes for other areas of the country  with low 
222 activity as well.   A 100 watt Q5 Signal transverter costs $840. 
This is a 500 WATT TRANSVERTER that includes the GPS reference all ready 
to go. All you do is supply 50 VDC and 0 dBm of 28MHz energy. I have not 
built the xverter up yet, but I expect the cost for the whole unit will 
be in the $750 range.  This does not include RF relays, but I could add 
that in at an extra charge.

So all of you 222 MHz ops who might know a suitable candidate for this 
rig, please beat the bushes and round up some willing ham and then let 
me know.  Depending on the circumstances and rarity, we will somehow 
pick out a "winner".  All in an effort to build some more 222 MHz 
activity. Speaking of which, I have been informed that QST will publish 
an article all about the "222 MHz Amplifier Project" at some time in the 
coming months. That will bring some attention to the band as well.

73

Dave K1WHS