Ham Radio

KR2M Mobile Antenna

2007-07-11T08:17:00.000-04:00

I recently purchased this KR2M mono-band 2 meter antenna from DJB Electronics, located in Jamestown, NC. They are an online store that sells ham radio equipment. I was extremely impressed with the quality of this antenna. Setup only took a couple of minutes. I unwrapped it, screwed in the antenna mount into the magnetic base, then inserted the antenna into the mount, tightened 2 screws, plopped it down in the center of the roof of my car, and connected my little Radio Shack HTX 202 HT. I had the HT plugged into the cigarette lighter of the car, allowing me to put out 6 Watts.

I tried the W4NC repeater. Success! I was happy just being able to get a signal out of this gully surrounded by apartment buildings in Winston Salem. So I decided to do a little more testing. I was able to get a signal out to the W4GSO repeater in Greensboro! Well that definitely had me covered. Exactly what I bought it for. My S-meter showed a 6 on transmit. A little reflected power. So I took the twisty tie that came in the packing, coiled about five turns of the coax loosely together (as I didn't have anything to wrap them around) as close as I could to the door (where the coax exits the vehicle) and secured it with the twisty tie. (quick n dirty 1:1 balun) Transmit showed S-9! Good to go.

So I proceeded to take my wife to work, then go visit my parents in Thomasville, NC. I made several contacts, including N4BYU, N8NQP, and a few others I can't remember off the top of my head at the moment. I was still able to hit the Greensboro repeater from all the way in Thomasville with only 6 watts! No flutter and no picket fencing! This antenna has quality written all over it! And after taxes and shipping it only costs about $18 bucks! James, the store owner, provided excellent customer service. He answered all of my questions, and even delivered the product right to my apartment door since he was passing by! Try getting that from some big, brand name, corporate outfit! I will definitely be purchasing as much of my equipment as I can from them. They even sell study materials! Time for me to prepare for my general ticket!

New rules could rock wireless world - Yahoo! News

2007-07-11T04:34:00.000-04:00

New rules could rock wireless world - Yahoo! News

The FCC head wants new wireless devices unlocked. This could have dramatic changes in cellphone provider costs for digital traffic. Could this be the final end in having to buy a new phone when we switch our service to a new provider?

In some cases, this is already here when you go out on your own and buy an unlocked device. However, this puts the burden on the consumer to ensure the phone is compatible with the provider. Perhaps this is the beginning of pushing that responsibility back onto the provider?

Ground Plane Experiment 1

2007-07-10T23:25:00.001-04:00

This is my first home brew ground plane antenna experiment. I attempted to design it for the 2 meter band. First, I purchased 2 of those aluminum throw away cake pans from the dollar store. I cut off the edges so I would only have the bottom. Then I folded it in half, then in half again, and again until it was firm enough (or so I though) to provide a good base for attaching my wires. I also cut holes for my antenna in the center, and 8 others around the edges of the aluminum sheet for attaching my ground wires.

Then I grabbed some wire coat hangers. I cut 8 of them to 24 inches for the ground plane wires. For the actual antenna I cut one to about 21 inches. I used a plastic PVC pipe to mount the entire thing on, so i could tie it to the railing of my balcony. (Apartment living has some down sides at times) I used a rubber gromet on the radiating portion of the antenna to insulate it from the aluminum sheet, then used electrical tape to hold it in place.

I left about 2 inches of the bottom of the antenna so i could bend it into a loop and have it stick out of a hole in the PVC pipe. This is for attaching the coax. I attached my ground wires by bending the ends through, and using needle nose pliers to secure them. Once finished, this wasn't very secure, and the aluminum began to bend. However, since this is an experiment, I decided to press onward. I took some 22 gauge copper wire and looped it around each eyelet of the ground plane wires, then secured all of it with electrical tape. I left some of the copper wire hanging out of the tape to attach the coax shielding.

The aluminum sheet i attached to the PVC using a combination of super glue and electrical tape. Once finished, I wasn't really impressed with this as it doesn't seem very sturdy. Then I attached the coax, and wound a tight coil around the PVC to form a quick n dirty 1:1 balun, securing it with electrical tape.

I took the horrid contraption outside for a test. To my dismay, it was horrible. It became resonant at 147.5MHz and above. Not quite what I had in mind. I tried taking a piece of copper wire and taping it to the radiating element, as well as to the ground plane elements to lower the resonant frequency. Nothing changed. I tried trimming the radiating element as well as the ground plane wires. Still nothing. In fact, it didn't matter what I did, it always stayed resonant at the same frequency range and above! This is extremely odd for an antenna. This was quickly turning into a scientific mystery, so I decided to trim the entire thing in short. Still, the resonant frequency did not change. So I dismantled it and brought it backcredibly inside. Back to the drawing board.

I suspect my problem arises from the fact that my feed point i about an inch below the ground plane. Perhaps only the lower half (below the antenna) was acting as a radiator? In any case, it calls for a complete redesign and rethinking of the antenna.

Notes: As I have limited funds, and limited equipment, I had to solely rely on the S meter on my HT. The test were performed using only 4 Watts of power to prevent harmful RF issues as well as damaging the equipment.

First Post

2007-07-09T04:57:00.000-04:00

I suppose all blogs start out this way, so here goes. Currently, I don't have a lot of cash to spend. However, I still have my HTX-202 radio I purchased from Radio Shack when I was 16 years old. It still works. Before putting it away, I placed a fresh set of AA batteries in. This has prevented the built in battery backup from draining completely. After all these years, it still works. (yes, I did remember to check the batteries every 6 months and replace them, to make sure they didn't leak) The radio functions just as good as the day I purchased it. I still can't find the rubber duck antenna, so I'm using a telescoping whip antenna. It works ok. It's just difficult to get a good signal out anywhere in this apartment. I've been tinkering with various antenna ideas however, so I hope to have this problem fixed soon. I am also studying for my General Class license, as well as saving up for a new radio. I'm not sure what kind I'll get. I suppose it will depend on how much money I can scrounge up. I'll worry about that when the time comes.