I currently have a pro-2055 and i want to scan freq's between 120mhz to 470mhz. The antenna i am running now looks like an older style radioshack antenna with a mag mount and what i believe are two coils. I can barely get a freq of 154 which is 20 miles from me.
Hmmmmmmm... I, too, have a few, actually 4, 2055s and also use the RS magmount with them, and my 2096s and 600s, both mobile and base without any problems through the VHF-UHF ranges. I have several signals that are around the 154MHz range you are having problems with, though, several of them are a problem of being ones I really do not have any interest in. Luckily I have been able to take care of *most* those via setting either a CTCSS or DCSS `tone' for the ones I want. (I've got one signal of interest that, unfortunately, doesn't use either and I am somewhat lucky that the `competitor' signal is fairly intermittant so I can still hear pretty much most of what I am interested in.) The closest site that I listen to is over 50 miles away and comes in almost like it was next door.
This makes me wonder about your problem given where you are. Did you just assemble your magmount by dropping/inserting the various `interconnecting' `bits-n-pieces' into their various `sockets' and tighten things down? I've carefully made up all the connections such that the setscrews are only using approximately the length of the diameter of the setscrew plus about 1/16". (I *did* try replacing some of the other mast pieces with slightly longer pieces but all of my `kludges' really never made any really noticable improvements. Though, I will admit that replacing the top mast section *seemed* to make a just noticable improvement on the VHF-Lo end. The `fly in the ointment' was an almost total loss of the UHF-Hi end.)
I expect that there will be replies about "How does such tiny length differences make such differences?". While I could just make either "FM" or " It is sometimes just the way things go." type of reply? Instead, based upon many years `playing' with both scanners and actual 2-way radios, my response is that *sometimes* it works out that way because one is only just that `tad bit' off from the antenna's `sweetspot' for that particular setup and good old `plain luck' has reared it's head for you. Since we are talking about just receiving I suspect that this may be the case for you and while it is seemingly an easy way out to just go and get another antenna and just call the existing antenna a #@&%$@# piece of junk.
As you might gather from all the preceeding text I tend to look at the situation as something to `play' with. Since you already have faced the proposition that you may have to go out and purchase another antenna this opens up the `field' of what you may want to try *before* springing for that new antenna. (Now... Something I should warn you about, mainly because I *don't* know if you have had the not so wonder experience of cutting the material those `bits-n-pieces' of mast are made off. *DON'T* try and cut them with a plain old pair of diagonal wire cutters! You *might* get away with that doing one or two cuts but, unless the `dikes' are specifically made for cutting `hard' wire you will end up with notches in the, once nice and sharp, cutting edges. [I have even seen small `bolt cutters' end up notched!] The very best way to cut, both for saving a good pair of `dikes' and producing nice smooth cuts, is to use a cutoff disk with a high speed rotary cutter, AKA Dremel Tool, to notch the mast material on 2 sides, put the work in a vice and then snapping it, and then `dress' the end with either a grinder or grind wheel and the `Dremel'.) Find some place that will sell you a stick or two of some stainless steel welding rod, or `round stock', the same diameter of the pieces you are going to be playing with. Keep the original pieces and cut yourself some pieces that are, maybe, to begin with and try them in place of the originals. (I'd cut several different pieces of different lengths for all three pieces with +1/2', +1", +1 1/2" *and* -1/2", -1", and -1 1/2" `additions'/`subtractions' knowing that I *may* have to make `adjustments' to those as `playtime' proceedes.)
Next comes `playtime'. {VB GRIN!} The very first piece *I* would play with would be the top most one. This is, most likely, the one that handles the range of frequencies you are currently interested in. I suspect that if I am wrong there are others here on RR who will willingly jump in and correct me. (Don't worry about the `tip' end. Once you find out if that is what is needed all you have to do is just gently round off the end and slip on and shrink a small piece of heat-shrink tubeing, bright red is the best, to both protect it and make it visible.) Since you know what
Frequency/Frequency Range you are the most interested in at this time your 2055 can be your `indicator' as to whether you are going the right way. (Keeping a set of good notes whilst you are playing will
greatly help! Especially if you find that you have to `play' with the other mast sections!) Once you have found the `right' length for that frequency you can then, depending upon if you discover that you've caused a problem at another frequency, `play' with other pieces of the mast.
If you do have to play with any of the other mast sections your notes will help you know somewhat which way you have to go with the others
and how much you might have to add or subtract to/from previously `tuned' mast sections.
Now... I suspect that you may be muttering something along the lines of, "Why should I `play around' with all the above?" You may probably be right that it sounds like a PITA and can just tell me to `bugger off'. But, not only is it actually fairly simple to do it also kinda fun to both do, being able to say that you have done it, you have made you receiver `hear' better,
and you have a true `one of a kinda' antenna has it's `plusses'. Not only all that, without the cost of getting a Dremel (Which is something that will pay for itself as time passes.), even with the costs of the mast material and various `disposables' will most likely be a lot less than a new antenna. Oh, SWMBO just reminded me, yeah there also is just the "I did it myself!" `glow' you will have even if no one asks.
If you need to ask me any questions you can PM me and I'll try to help.