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
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