222 on a shoestring

Bob G. ACØKC

Yes, that old Dow Key DK77 relay needs to go. The 401 series that Dave mentioned is nice, but several hundred dollars. Ouch! I doctored the relay before (picture) and after (picture), but like Dave says, it *IS* ancient. . .

Maybe I just need to find that “round tuit” and work on the PIN diode switch. Have diodes, need to build & test the quarter wave section, either lump components or a piece of coax.

The whole thing still needs a housing/chassis also (picture).

Home brew 30w amplifier based on a RA30H2127M glued to a slightly modified DEMI 2.3 GHz stock PCB is still working well. (picture)

Top of the heat sink was actually sanded flat with an orbital sander after drilling & tapping it for the board and module to prevent cracking of the internal substrate. (picture)

I had to add a 6dB pad on the input (not shown in these photos,) using three chip resistors cut into the input trace on the left side.

Got a nice piece of plastic out of Drew’s “free” bin at Colorado Plastics last week that’ll be a perfect boom for rebuilding the 222 MHz 6-element “Cheap Yagi.” The design is from WA5VJB’s website.

Right now, that’s welding rod & rather warped scrap lumber. Works well enough that I think I’ll keep the design and do it right.

Do have six BX tower sections lying in the yard, but it’ll be a while before that’s up and operational. . .