Discussion in 'Mobile Radio Systems' started by KD5AUU, Feb 3, 2011.
Could I talk you into sending me a picture? firstname.lastname@example.org
Unfortunately, I don't have a picture of the Texas Bugcatcher loading coil and it is presently loaned out to a university in another state that is running valid delay measurements on it. I searched for pictures on the web but didn't have any luck.
Oh well...............thanks anyway
Here are some images from the web:
Cecil - is that a 160 meter coil In the pictures? If it's an 80 meter coil then I may be way over estimating the size. I'm guessing the center post is 1-1/2" with the overall diameter roughly 6" and the coil itself about 15" long not counting the extension of the center post and connectors - Would you say I was in the ballpark or out in left field somewhere?
The two big ones are probably 160m coils. The small one is probably a 40m coil. As I said earlier, my 80m Texas Bugcatcher loading coil is 6" diameter, 4 TPI, and 6.5" in length, i.e. 26 turns of #12 solid copper wire.
The smaller coil pictured is a remotely tunable coil - I saw the prototypes for it at one of the Belton Hamfests years ago - It works similar to a screwdriver antenna. I knew a couple of guys that had them but couldn't keep them working. Anyway I have already started a parts and materials list and I have a mast and an inductance coil for a matching setup but I have one more question for you and then I guess I'll just start experimenting - Do you have any Idea where the 80 meter Texas Bug Catcher resonates without a tap being applied. (If you hooked up an analyzer to the fully assembled antenna with no jumper)
You need to give me the specs/dimensions of the "fully assembled antenna". Where is the loading coil located on the antenna? Base-loaded or center-loaded? I have an EZNEC model of the loading coil.
Center loaded - three foot mast - full 102" whip - no capacity hat - won't be running it mobile but will be mounted on my truck when in use. Base of mast will be at top of back corner of truck bed
Well, EZNEC says it will resonate close to 3.9 MHz over mininec ground but that's not correct for mobile operation. Based on my experience, I would guess it will resonate around 3.6 MHz without jumpers. Where do you want it to be resonant?