Field Strength Meter

I’m going to use this new old stock Simpson panel meter for a field strength meter. I’m thinking of making it Arduino or Raspberry Pi based so it can be made wireless – have the sensing circuit out in the yard and it sends data and have the meter in the shack. Kind of a weird digital – analog mash up. There are many…

U.RAT Version 2.0 and Experiments

The u.RAT that I will set up tomorrow will replace the Palstar BT1500A, but only as a test – to see if two Palstar C600 variable capacitors plus one inductor will work on 160M. I expect it will work on 160 and 30M, but not sure about 80M. I split the control box and the drivers so that the Raspberry Pi Zero is in…

The S and Z Match for the URAT

I was going to disassemble the u.RAT and re-use the components, but I have just come into a second variable capacitor – which is the Palstar C600, a true work of art. I am trying to get rid of having a roller inductor in the circuit, but would much rather have a switched inductor. Yesterday I posted this circuit: And the Palstar BT1500A has…

Collins 32-V3 Antenna Tuner Circuit

I stumbled on a suggestion for a balanced tuner circuit that is suggested in an old Collins 32-V3 transmitter manual. The top circuit is one that I am most interested in. I’d love to try it and compare it to the Palstar BT1500A – which works perfectly, but it would be super if I could use the URAT with two variable capacitors and a…

Balanced Vs. Unbalanced Antenna Matching

I’m going to add the URAT to a 70′ tall wire vertical with 96 buried radials, and this is a classic 80M quarter wavelength vertical. Its an unbalanced feed with an unbalanced antenna. It will require an L matching circuit: I like VE7BPO’s diagram, and I am guessing that I will need to wire the variable capacitor and roller inductor using circuit B, but…

The Future of DX-ing and DXCC: ROBOTS!

I’ve been grappling with this for a few years, ever since I was involved with fund raising for VK0EK. I don’t think the average DX-er really knows what a big job it is.  The funniest thing about this blog post is that it came about while sipping a very nice Uinta Detour Double IPA and just sitting back and thinking – musing about the…

First Stop on the u.RAT World Tour: EBARC in El Sobrante

I will be giving my first Maker – Ham presentation at the EBARC meeting this Friday: 7:30pm, Friday, August 11th, at the El Sobrante Library on Appian Way This will be my “warm up” for Pacificon, and several Diablo DXers will be on hand    

U.RAT Ready for World Domination!

The final part of this u.RAT “science fair project” is wiring the variable capacitor and roller inductor with a 50 ohm dummy load resistor and then attaching the Rig Experts AA-30 so we can see how tuning the components affects SWR and what the L, C and X values are. I have been playing with different “equivalent circuits” and using a 56 ohm as…

The u.RAT as an Educational Platform

What started out as a personal project – to use the Elecraft KPOD to control the Palstar BT-1500A, has turned into an educational platform that I can use to write articles and give presentations at Makers Meetups and Ham Radio Club and convention gatherings. I’m giving my first urat presentation at EBARC in San Pablo in just two weeks –  August 11. EBARC has…

U.RAT Video Wrap Up

Here is the full on video for the u.RAT: