I was in the process of expermenting with using random length wire antenna(s) for my BR330 scanner, when I accidently notice something, and decided to try and go somewhere with the "discovery".
Basically what I ended up with is as follows.
A simple old Radioshack 300 75 ohm matching transformer hooked to a female coaxal - to - bnc adaptor, which then was attached to a male bnc - to - sma adaptor, as this scanner has a sma for the antenna terminal. I then connected a 18 inch telescopic antenna to only one of the connections on the 300 ohm side (one of the 2 connectios on the 300 ohm side seems to work better than the other). The other terminal was left unused - as if it was not there.
To my surprise through nearly all spots on the bands I checked, this setup performed more like a much much larger antenna, better than an old 6 foot telescopic whip I once purched on ebay - i think form someone in the UK.. The areas of the spectrum it seemed to not have much of an impact on was on the LW/MW bands and between 420 - 450 MHz.
On the 800 - 900 MHz bands it worked best when I shorrtened the antenna to around 6 - 8 inches.
At first I was almost certain that I was causing major regenerations between the balun and my scanner, because the balun I used iwas housed in plastic.So I tried placing 25 feet of double shielded coax between the scanner and antenna/balun and it still worked quite well. So I pretty much rule out regeneration.
I went out of my way to hook up a second identical antenna to the unused terminal on the balun
and when iI did - I lost all of the "gain" that I was getting.
So whatever may be happening here.....
And not to look a gift horse in the mouth - should that be the case
I have been going crazy trying to figure out how this "gain" is coming about.
As I said this was an accident, and if it's one that is worthy, i'd like to know if anyone can tell me
what I have done - i'd lke to understand how it does what it does, not just what it seems to do.....
And equally important.... could it cause damage to my scanner....Untill I really know atleast this --- My little "discovery" will stay put in my desk.
Thanks for any information anone of you may have.
Basically what I ended up with is as follows.
A simple old Radioshack 300 75 ohm matching transformer hooked to a female coaxal - to - bnc adaptor, which then was attached to a male bnc - to - sma adaptor, as this scanner has a sma for the antenna terminal. I then connected a 18 inch telescopic antenna to only one of the connections on the 300 ohm side (one of the 2 connectios on the 300 ohm side seems to work better than the other). The other terminal was left unused - as if it was not there.
To my surprise through nearly all spots on the bands I checked, this setup performed more like a much much larger antenna, better than an old 6 foot telescopic whip I once purched on ebay - i think form someone in the UK.. The areas of the spectrum it seemed to not have much of an impact on was on the LW/MW bands and between 420 - 450 MHz.
On the 800 - 900 MHz bands it worked best when I shorrtened the antenna to around 6 - 8 inches.
At first I was almost certain that I was causing major regenerations between the balun and my scanner, because the balun I used iwas housed in plastic.So I tried placing 25 feet of double shielded coax between the scanner and antenna/balun and it still worked quite well. So I pretty much rule out regeneration.
I went out of my way to hook up a second identical antenna to the unused terminal on the balun
and when iI did - I lost all of the "gain" that I was getting.
So whatever may be happening here.....
And not to look a gift horse in the mouth - should that be the case
I have been going crazy trying to figure out how this "gain" is coming about.
As I said this was an accident, and if it's one that is worthy, i'd like to know if anyone can tell me
what I have done - i'd lke to understand how it does what it does, not just what it seems to do.....
And equally important.... could it cause damage to my scanner....Untill I really know atleast this --- My little "discovery" will stay put in my desk.
Thanks for any information anone of you may have.
