Well since Dave has difribulated activity on 222 and now there's growing
interest I wanted to pass along a way to possibly increase your signal.
I have a number of amplifier boards removed from VHF TV broadcast service.
These were pulls from Thomcast / Thales transmitters. These boards have a
BLF278 as the active FET and easily make 250 to 300W for each FET. They
take about 4 to 5 watts to in for 300 out. The boards have 2 independent
amplifier circuits and FETs on each. They are VERY EASY to put on 222 and
a few more mods make them work on 2 meters. These are just the boards with
a FET....no heatsink, box, relays etc... I can provide the documentation
for either band. I'm looking to get $75 per amplifier plus shipping. If
you want a double board I'll sell those for $150 shipped to you as I don't
have to cut them in half. This is a working amplifier board with a tested
FET for less than the cost of the FET itself. Let me know if any of you
are interested in any of these. Maybe it'll help make 222 a noisier place
to be!
73
Fred
N1DPM
On Tue, Jun 22, 2021, 10:45 AM David Olean <k1whs@metrocast.net> wrote:
> It is Tuesday and that means that there will be all sorts of activity on
> 222 MHz. If you want to check out the latest update to your 222 setup,
> tonight is THE night to check it out. KA2LIM in western New York will be
> checking out some mods that he made, and I will be trying out version 3
> of my high voltage power supply. Version 1.0 was just ugly and crude.
> Version 2.0 was very pretty and used 12 X 2200 MFD 550 volt electrolytic
> capacitors in a big capacitor bank. After having a very robust arc
> event that took out my HV fuse, I calculated the energy stored up in
> those capacitors, and decided that I had gone overboard a little bit. I
> mean 183 MFD at 5500 volts does seem a bit big! 1600 joules of energy
> is not trivial. I also had a failure of one of the 12 equalizing /
> bleeder resistors, and that got me to thinking that using a bunch of low
> voltage capacitors in a high voltage power supply was not a good idea.
> Yeah, I know, everybody does it, but I felt more comfortable having a
> single high voltage rated capacitor and a honkin' 200 watt wire wound
> bleeder resistor. Hence Version 3.0! I now have a 30 MFD at 5 KV non
> PCB capacitor installed along with an 80 Kohm 400 watt bleeder
> arrangement all set for this evening on 222 MHz.
>
> Yes, I know that there are many areas of the country where activity is
> rather sparse. All it takes is two stations to get on and make a
> contact. With the availability of chat pages now, it is a simple matter
> to find someone at a suitable distance and try a difficult sked over an
> un believable distance. You might surprise yourself. I know that
> Marshall, K5QE (Bless his soul) gets on for Tuesday night, and has no
> local activity, so he tries to drum up a meteor scatter, EME, or tropo
> scatter sked every Tuesday. We need many more stations to be active in
> out of the way places to try to extend our collective range. This is how
> we can maximize our stations. Try something difficult! 900 miles is a
> good meteor scatter distance. Tropo scatter can work out to 400-600
> miles depending on your station and whether you can catch a tropo peak.
> Last week, I managed to work KO4YC at 525 miles while running 80 watts
> here. I don't know how Cornell managed to copy my flea power, but he did!
>
> I will be QRV at about 7 PM (2300 UT) on 222.1 or thereabouts. Try to
> make an appearance and make a contact or two. It should be showery along
> the East coast, so it is a good time to be inside and on the radio.
>
> Dave K1WHS
>
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