"IPD" homemade antenna.

Joined
Jul 8, 2007
Messages
809
Location
Northeast Nebraska
Ideally, I'd rather have an antenna on the roof, but going to keep my Wife happy! Here is a small antenna improvement project I have been working on.

As I was looking to improve VHF Hi signal strength on a Larsen LMO 220 (yes its made for the 220 ham band), I did a bit of tinkering around with a metal cat litter pan (never used!)a couple of elements off an ancient Radio Shack 20-032 and a piece of strong-tie.

The Larsen actually did a decent job by itself down to the aircraft band up towards the 70cm ham band, but dropped of quite a bit towards UHF. But there is very little in the way of UHF minus businesses at my location that are over on DMR or Mototrbo. The only 800mhz I have is local law enforcement, not a factor since the site is in town.

The cat pan acts as a ground plane for the antenna. I then attached the strong-tie to the cat pan with a couple of 1/4 machine screws, attached the Larsen antenna to the tie, which the bottom of the antenna is a trunk lip mount, perfect for attaching to the tie, I was going to swap out the coax from the antenna to some RG8X, but left it alone.

The 2 elements were parted out from a Radio Shack 20-032 mobile antenna using the top and middle elements. 2 holes were drilled into the pan, inserted and glued in. The elements are not physically attached to the coax but act as a "radiator" to increase the gain a bit.

So far, I am surprised with the improved performance. I have 5 Nebraska SRS towers near me. 1 is local, I can hear it with a paperclip stuck into the antenna jack of my Pro106. The other towers are Humphrey, 20 miles south and Elgin 25 miles west. With both of these towers, I now have the control channels coming in at 99% decode, 4-5 bars on the signal strength meter, prior they were hovering around 70-80% 3-4 bars with occasional pixelating on received transmissions. Rattlesnake Creek, about 30 miles east, the control channel is readable but not strong enough to decode. I even picked up a couple more bars on my local 800 tower!

I did give this antenna a name-Imperial Probe Droid antenna, as it sorta look like the top on the droid in the Empire Strikes Back.

IMG_20230518_163254367[3842].jpg
 

dave3825

rebmeM evitcA
Joined
Feb 17, 2003
Messages
5,947
Location
Suffolk County NY
Ideally, I'd rather have an antenna on the roof, but going to keep my Wife happy!

Do what I did. Everytime wife asks why there are cops or fire trucks down the block, say I really do not know. My antenna is not really picking them up that good. If it was on the roof, I would have heard the call..
 
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