CQ CQ CQ -- Let's Play Radio

About this page...

This page is written by John Phillips, KA9PGC. That's John playing radio in the above photo. John recieved his Electrical Engineering degree from Purdue University. Go Boilermakers! This page is John's helpfull hints and tricks to make your radio experience better.

Grounding your Mic.

Todays grounding trick is an oldie but a goodie. First picture is my microphone cable going thru a ferrite core and then to the radio, Ten Tec Omni V. On most radios there is a compromise of sorts at this point. On this radio the ground goes from the connector to the pc board. The ground pin really needs to be ground also at the chassis. What I did was to solder solid wire at the ground pin of the mic connector and ran it out of the connector and connect it to the clamp of the mic conector shell. This modification also means that ferrite core I have on the mic cable will be more effective in isolating the microphone. On this radio, that ground is both ptt and audio. Some radios have a separate ground for both PTT and TX audio. Under those situations if your application requires crossing both of the grounds together, this is a must, and cross them at the radio. The example is using a Kenwood MC-60 microphone which has this and using it with this Ten Tec I have. The Kenwood microphone otherwise would have a voltage difference in its grounds. Another way of saying ground loop. Grounding of the mic like I did is simpler than what some of the postings on the internet to tame that kenwood microphone. Years ago did that when that microphone was connected to Kenwood ts-430 which it was designed for.

Morse Code Keyer

Just finished morse code keyer kit by midnight design solutions.

The paddles are homebrewed from my Dads lathe years ago.

http://midnightdesignsolutions.com/

Motor Cycle HF

Portable Antenna Stand

Looking for a light weight, stand for your verticle antenna? Here is a quick easy solution. Take a hunters stand, you can find them for around $100.00. Remove the seat and mount your antenna. You might want to beef up the grounding, on the legs, but all in all, it is easy to carry and easy to set up. Perfect for Field Day or camping.

Ground Loop

Even the simplest radio install has ground loops. At home or your mobile creates a ground loop. If you don't have the time to search for the proper ferrite torroid, you make one with 15 feet of your power cable either wrapped around a 4 inch long pipe nipple. Or you can do as I did, a stack of 4 steel washers, 2 inch ID. On each end of the cable I have also installed a .1UF capacitor.

Just install this choke as close to the radio as possible. Your ground loop in the mobile is a grounded antenna and your negative battery connection. If the radio is mounted to metal, there is your other ground loop. You have eliminated the the dc caused ground loop with one choke. Now you might need and isolator on the antenna coax close to the radio. Snap on toroid kits are available for that task.
So what about the home QTH? Same thing. Your power supply is grounded to the house wiring. THIS IS FOR SAFETY. Some expects say eliminate that connection. Do this ONLY for trouble shooting. A 3 pin to 2 pin ac adapter can eliminate that ground loop but for 50 cents, is your own safety worth more? With all the interconnects we may do at the home setup, next month we will address some of that.