W4DEX  VHF - UHF Page

 

Picture of antennas taken from another tower several hundred feet away.  Small mountain in background is Morrow Mountain 17.5 miles ENE.  Summit of the mountain is about 75 feet higher than the antennas.


I am active on all VHF-UHF bands with the following equipment:

50 MHz    Antenna is a 1970 T match Hi-Gain 4 element Yagi (top right on H frame).

A copper pipe J-Pole with a 4:1 coaxial balun out the top is used for FM operation.  SSB/CW transceiver is a Yaesu FT-620B (Oldie but goody).  Amp is a modified AM-1180/GRC running a single Collins Y-400 (4CX-250R) tube.  FM rig is an Azden PCS-7500H

 

144 MHz    Antenna is a 12 element KLM original flavor (bottom left on H frame).  Rig is a Yaesu FT-221R which drives a 100 watt solid state amp.  A  pair of 4CX250s built and used years ago sets idle waiting for me to get motivated enough to put it back in use.  The amp power supply was large and the shack ran out of room.  I need to build a smaller one.

 

222 MHz   Antenna was a Cushcraft Boomer from what I've been told.  I bought it at a fest primarily for the material.  It was longer than what I wanted to put on the H frame and I didn't want to use the boom braces.  After strengthen the boom center W3IY helped me model this into a optimum gain 14 element  Yagi (bottom right on H frame).   Rig is another Yaesu FT-620B used as the IF for a Microwave Module transverter.  The amplifier is an AM-6155 which has excessive blower noise which I have been told is normal.  (going to work on that blower noise problem one day)

 

432 MHz   Antenna is a Cushcraft 424B, 22 elements on a 18 foot boom  (top left on H frame).   I once had 4 K2RIW design19 element yagis on a H frame on this tower.  I made a dozen or more EME contacts with the 4 antennas but never heard my echoes.  As I added more antennas to the H frame I began to notice the 432 antennas were not working as well.  So I replaced them with the one antenna which seems to be about as good as the reduced performance of the 4 antenna array.  The old saying "You can't have your cake and eat it too" seems to apply here.   Coax for this band is 7/8" Heliax.  The rig is a Yaesu FT-101ZD HF transceiver used as a 10 meter IF for a Microwave Module transverter.  Output from the transverter drives an IPA (intermediate power amp), a modified Motorola T-44 2C39 amp.  The IPA drives a K2RIW design  homebrew pair of 4CX250Rs.  A few amp pictures can be seen here:  riw432amp1, riw432amp2.

 

903 MHz   Antenna is a 33 element loop Yagi from Down East Microwave (just to the right of the dish) fed with 7/8" Heliax.  Rig is a DEM 902-144CK transverter (a beautiful kit) with a Yaesu FT-221R for the IF.  A 160 watt solid state power amp and a commercial preamp helps the signal coming and going.

 


 

 

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