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20060202 2006 February 3

Posted by kc2ped in Uncategorized.
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I was at RadioShack today stocking up on some batteries and went browsing through the components drawers more to see what was there than to buy anything. One thing lead to another and I am now on the way to building a 1/4-wave ground plane antenna for the radio that I don’t own yet.

I saw in the study guide and on the net plans for building a simple antenna where the radiator and director are made of brass welding rod and are soldered onto a chassis-mount UHF SO-239 coax connector. End of story. It is simple to build and should be fairly cheap. So when I came across a SO-239 connector in the drawer I had to get it. Then I got a pair of solderless PL-259 UHF-Tupe connectors to use with it. Now I am searching for the welding rod.

On the Home Depot web site I found bronze brazing rod from Bernzomatic, but no brass welding rod. So I Goggled the stuff and got a hit for an airplane building/repairing/restoring supplier. But when you get to the PDF it is bronze brazing rod again. So now I need to find out what the difference is between brass and bronze so I can see if I can use them interchangeably.

I found on anvilfire FAQs that brass and bronze really aren’t all that different.

“Forging Brass”
UNS C37700
“Architectural Bronze”
UNS C38500
Copper 59.5% 57%
Lead 2% 3%
Zinc 38% 40%
Unaccounted
For
0.5%  

But that difference is probably enough to give them a different resistance which might require a different element length or other adjustment. So I need to find an antenna Elmer who can set me straight. A question to ask at class.

I have been listening to my short wave radio a bit lately and have actually heard a good bit on it, although not WWV. A lot of what I do hear is religious programming coming out of FL. But I have noticed that sometimes the static level will drop markedly like someone had turned off the static switch. It turns out I have done it in a matter of speaking. I noticed quite by chance that my computer monitor went to sleep one time at exactly the same time when the static stopped. So I woke the monitor up again and the static returned and when I powered it off the static stopped. At least on that frequency. So while I was rummaging around in the drawers I came across a blister pack containing two ferrite cores that hadn’t been opened yet so I bought that thinking I could run some of the wires on the back of the computer through each one and hopefully cut out some of the RF interference. It turns out that these things need to have multiple turns of wire wrapped around them so they won’t work for more than one wire. I need to get a bunch of the long cylindrical ones that snap around the wire. I did wrap my radio power cord around one of them but it didn’t seem to change anything. I suppose I could wrap the antenna wire around one but blocking the RF in the antenna wire defeats the purpose of using the wire in the first place. I also need to get the metal cover back on this machine.

I am getting bogged down in the chapter of the study guide on electronics. And I may get bogged down some more. CompUSA called and said my laptop is back from the shop so if they have actually fixed it this time I am going to have to spend the next couple of days doing Windows Updates then a couple more downloading and installing software. I am not terribly worried though. I have been taking a practice test every day at QRZ and am coming in in the high 80s-high 90s so will have to get unlucky in what questions they ask or sloppy in the way I answer them to fail the test.

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