This mic rocks on the air!

Sky’s Daughters 746 FAQ PDF Link
My local link to the 746 FAQ PDF

1) The Pocono Hamfast was an unfortunate bust. We drove 70 miles from our QTH in Pottstown, PA, to be faced with a “less than mediocre” hamfest. Only 1 vendor listed on the flyer was there and they were only selling power poles and HT cases. Honestly this has to be the worst one I’ve been to yet, which was quite unfortunate.

2) With the upcoming 2009 CQ RTTY contest this weekend (Sept 26-27) I’ve enabled digital modes on Laurie’s Heathkit SB401/301. I took a hint from another ham using the HD15 phone patch as a computer interface for a DVK (digital voice keyer), I used our SB-630 station console for PSK/RTTY/SSTY instead. It was quite simple to do even though their appears to be a 550 ohm impedance difference between the computer and the phone patch interfaces. So far so good. Posts with photos coming soon.

3) I recently aquired an IC-2200H for the truck. Even though it’s only 2 meter, it gives me better D-Star capabilities down the road. My interest in D-Star has been waning as of late. Packet loss and “R2D2′ing” gets old quick, especially when you are a member of net operations. Thoughts of selling my 91AD for this reason have been plaguing me lately. See my recent D-Star post.

4) After spending an afternoon with my local radio club (DLARC) and speaking to a fellow ham, I’ve been introduced into the world of Hex Beams and Cubical Quads. I’ve never really investigated these types of antennas as they’re not considered to be the “conventional beam”. I’m happy to say after doing a bit of research, I’ve started building the base of the antenna and am quickly aquiring the parts to build the rest of the antenna. It seems all the commercial vendors want $100 for a hex base. I really wanted to go with the DX Engineering base, but decided to go completely homebrew instead and spent $30 at The Home Depot last night on parts. As I build this thing I’ll post my experiences and photos as I progress.

Here’s what I discovered:
Upon disconnecting the RG8u feed from it, I had no differential between the ground bus nor the cable shielding. This indicates a proper ground from the bus to the radio, which is where the cable shield is connected to.

After lifting the ground strap from the radio so the radio appeared to “float” electrically, I still had no difference in ground. I soon remembered that I previously hooked an audio line between her receiver and her computer so she could decode and monitor RTTY. When I pulled the audio cable, a 60 VAC differential appeared between the ground bus and the radio’s chassis.

Here’s why:
The Heathkit radio is powered with a 2 wire AC cord unlike the newer radios with external power supplies feeding 12 VDC to the radio. The DC power supplies bond the negative side of the circuit to their chassis ground, which in turn is then usually fed via a 3 prong power cord with ground. Since the Heathkit is essentially floating via AC, they probably attached chassis ground to the neutral side of the power feed. So when you compare the difference between a station ground and chassis ground, 60VAC appears, one half of a 120VAC house feed. Hopefully your not comparing the difference with your hand. It’s definately an attention getter.

One of the things to keep in mind when you start introducing voltage differentials and computers, you run the risk of damaging computer components. Think about it for a moment. The radio is floating electrically and your computer is grounded. Now you attach a 1/4″ to 1/8″ wire from your radio to your computer. While your pushing that connector into the computer’s Line-in jack, it’s possibly contacting other non-ground pins on the audio card, unleashing the voltage difference between the radio and the audio driver circuits in the computer. POOF! Your sound card or motherboard could be woofed. Mine didn’t, that I’m aware of.

Lesson learned: Ground your components before interconnecting them.