Archive for the RF Category
I had a difficult time finding this documentation so I’ll post it here for anyone whom may need it in the future.
This is for a Glen-Martin (G-M) MT-1845 50ft crank-up ground-mount tower. This is the same tower found on their TT-1845 (trailer mounted 50ft tilt over tower), but with a base plate for direct ground mounting.
PDF Document for Base Plate/Concrete Requirements: Chb13-18
PDF Document for Tower Specification Drawings: MT-1845
So, an opportunity has recently presented itself.
I have had a 32ft narrow gauge tower in the air since 2001 holding up some various Ham Radio antenna (3-element 10/15/20m beam + rotator & a 20/40/80m home-brew trap wire antenna). It is a tower that requires guy-wires when cranked up, and is not something I REALLY want to move anywhere. Plus it is ~17ft collapsed.
I was offered, in trade for some automotive work, what I estimate at being a 40-45ft crank up potentially self supporting aluminium tower. No idea what it was doing in its previous life…but it is down, on the ground, ready to go. Yay!
I am thinking this, combined with some vehicle mounting, and a nice UHF folded dipole antenna, can give me a pretty nice setup for the UHF repeater toy I just acquired. Command vehicle here I come.
I still want a pneumatic or hydraulic cylinder type tower for the Unimog 🙂
I’ve been working lately on an application for licensing up some UHF frequencies (mainly Itinerant, Low Power, etc.) so I can have some breathing room on UHF commercial. I really don’t want to use a frequency coordinator (extra $$$ in someone else’s pocket), but it would be nice to have some freq to use for whatever.
I recently scored a Riton RRX-450 UHF 5Mhz split repeater…so I am super stoked about that. After some ‘hunting’ on the net, found some software, and used a ICOM programming cable to interface it with my USB port. Win! Fully programmable digitally synthesized UHF repeater, with duplexer. Even narrow band! (12.5kHz)
Out of curiosity I contacted one of the Frequency coordinators (office FCC appointed!) and they were very snarly towards my request. Perhaps actually having LMR background is intimidating. Either way, definitely not getting my dimes.