Honestly Dan, it was the entire vhf hi spectrum being completely uncopyable that spooked me. That was a little over the top for me. To me it sounds like a simple matter of this particular radio missed a final trim or something. Impressive uhf reception, yeah, but no cigar. So I thought I would try your trap idea with the 785d which always suffered in those ranges and was always 90% deaf in the 108-134...not any more. Sad to lose the 197, happy to gain back a good chunk of the old 785d
I still have an eye open for that next scanner.
thanks again for all your help!
Hey Ridge, I have the same problem with all the modern GRE made scanners. I myself am many miles from any FM transmitters but the FM trap that the others have mentioned can make a world of difference.
It sounds like you discovered that with your 785!
In my case, an FM trap did not help at all. I had to identify and then attenuate the local VHF paging frequencies near me. I have several on all the large hospitals that are within eyesight of my location. A few of the paging transmitters run almost 100% duty cycle here and they caused my GRE's or RadioShack clones to desense badly in the VHF band. I could turn the attenuator on and get some help but then I lost some of the weak stations I like to monitor. I finally invested in some PAR filters tuned to the two VHF paging bands near me. They worked super fantastic!
I still get desense from one or two of the county police transmitters that are also right next door but they are not transmitting that often so they do not bother me much.
The desense was so bad from the paging signals here that I also could not hear the NOAA transmission which is usually a +10 over S9 on an Icom R9000 here.
Someone else mentioned another manufacture of notch filters to me the other day that were the same type as the PAR Electronics filters. I seem to have lost that post though. I wanted to check them out.
Your case does sound like an FM broadcast signal problem though being as it helped wonders on your 785D.
Do you also have a decent air band bandpass filter? Those also work wonders if you are in a high RF environment and enjoy monitoring the civil air band. Some of the FM traps like the radio shack trap will attenuate some of the lower air band but that is usually not a problem being as there is no voice really in the lower segment of the air band.
You should get yourself an air band filter if you are into air band monitoring and you do not have one. I have an older one made by AOR and it kicks butt. There is an ATIS transmission here that I cannot hear at all even with an Icom R9000 or R7000. Stick that air band filter inline and I can here the ATIS signal perfect! The signal is still weak but I hear it with no static.
Does anyone know of a military air band bandpass filter?
That would be one I could use here but I've never seen one.
I enjoy the military air band as well as the sat stuff in the same band but all the local RF around me usually knocks out the low power sat stuff.
Run yourself some searches from 152.000 to 153.000 and 158.000 to 159.000 MHz and see if you have many hot paging transmitters. It's the ones that give a full signal with just a paperclip (or nothing!) in the antenna socket that will cause you overload or desense problems with the GRE's. Uniden's will do it as well but usually not as bad.
The modern GRE's have an overly sensitive front end. Too sensitive in my book as it makes them almost useless if you live in a high RF environment.
The built in attenuator will often get them working again but at the expense of the loss of weak signal level stations. That is why I decided to use notch filters and eliminate the offending signals that caused most of my desense and/or overload. Using a specific notch filter, I can still hear my weak signals and my radio no longer appears deaf in the VHF High bands.
I never hear anyone really complain much about desense or overload problems in the 450 UHF bands though so maybe the front ends are not as hot in those bands. I have the same strength paging signals here on the same hospital roofs but in the UHF band and oddly enough, I've never had any problems caused by them on any of my GRE's.
PAR also sells an FM band notch filter like the one from RadioShack but it works better ( and costs more!). I bought one from PAR even though they are really not needed here. I ran some comparisons with the PAR and several of the RadioShack FM traps. The PAR attenuated the signals a lot greater then the radioshack trap did. I also found that the radioshack traps were not tuned equally. Some were so far off that they offered no attenuation of the FM broadcast band. They either attenuated the 20 MHz swath completely above the FM band or below it. I could fix them by removing the back cover and tweaking the coils but a drop to the floor would knock them out again. Maybe the newer ones use wax or epoxy to keep the coils from moving. Mine are all several years old and had nothing to hold the coils in place in case of a bad drop or smack with a hammer!
I still take some with me when I travel as I never know if I may wind up in a hotel near radio stations.
As far as the pricing on the 106 and 197 goes, I see them at the $300 dollar price point around here fairly often. Maybe some of the stores here are not company owned shacks.