OK, So what's up with my Pro 2052

[md_p97]

OK guys...open to suggestion here....

I have a RS Pro 2052, as many of you know, the date code is 03A03. Now I think there was an upgrade made to this unit that starts with the date code 04A03, but I don't know if it applies to my issues.

The first is with the Mont Co Fire Simulcast on 154.1600. I am continually receivng bleed over from this channel on just about any frequency I have entered in the 139.xxxx - 171.xxxx range. The closest tower to me is about 4-5 miles. I added an FM trap, at the radio end, in hopes of reducing the bleed through, but it has not helped. The simulcast on 153.9500 does not bleed through.

The second is with MSP freq's. I live mid way between Rockville and Frederick. I sit up on a ridge approx 100 - 200 ft above the rest of Montgomery Co. I hear the troopers and dispatch from Frederick just fine (39.4000) but I can only hear the dispatcher (39.3200) from Rockville. There is a mountain (Sugarloaf) that is between my house and frederick (I live not too far from the base). Interestingly enough, to add to the mix, is I can clearly hear the Carroll County Barracks and cars all the way out in Westminster.

I can also hear the low bands out in Jefferson County West Virginia.

You input and infinite wisdom would be appreciated.

Paul

 

[ka3jjz]

Paul, clearly on the 154.16 issue, you are getting overloaded. A FM trap won't help you here; with your elevation and the antenna's additional height, it's just too much signal for the old girl.

Obvious way to test this; disconnect the outdoor antenna and go with something indoors. If the spurs in that range are greatly reduced or go away entirely, the cause is clear. I suspect that will work, since you are not receiving any problems on 153.95

It's a shame that the 2052 doesn't have an attenuator (I think), because putting some attenuation on that frequency only might solve your problem. And a shorted stub might be too lossy on other frequencies...hmmm...

73s Mike

 

[KR4BD]

You can buy an attenuator from Radio Shack....unless they have discontinued it. I have one. It has 75 ohm inputs on each end. It is about the size of a cigarette pack and has an adjustable pot (control) on it to vary the amount of attenuation you want to introduce. It works well for me. If need be, I can get the part/model number for it when I get home tonight.

 

[ka3jjz]

A good thought, Tom, but it has one flaw - the attenuation would apply to every frequency he has in the radio, not just on one frequency. He would have to remember to set the attenuator to zero when he is not listening on that frequency, or to adjust it for some compromise value. Not the best solution.

Paul, if you are using a directional antenna, try not pointing it right down Montgomery's path...perhaps the attenuation from the side of the beam might be enough.

73s Mike

 

[md_p97]

Mike,

I am using the RS discone....I heard the trooper accident loud and clear....heard the trooper on his portable no less (sounded like he was still standing in the woods) when he called out that he had been struck. That is about 25 miles crow fly from me.

As for the Mont Co freq, well, like I said, its a discone...and I believe as you said...an attentuator would be across ALL channels, so that is not an option, though I do have to set the attentuator on my Pro-97 for the MSP rockville freq (39.3200) to reduce the interference I get. 270 is only about 6 miles crow fly from me. Via crow fly, you have to pass over 270, to get all the way out to 70....just doesn't make any sense to me.

 

[doctordave]

One other factor is that MSP "B" 39.4, MSP "G" 39.52 are tower broadcast simulcasts of 800 MHZ radio transmissions - so you will hear the cars & barracks equally strong from any location.....I have no idea if "N" 39.32 is repeated off 800....but if not, that could well explain the fact that you are only hearing the barrack clearly.

Also of note, I tend to get much more household electronics interference on 39.32 and a few other select MSP freqs. In fact, I get 4/5 SS bars lit up on my 895 with that freq, just from having my computer in the same room. Really zaps my range.

 

[md_p97]

Dave,

I don't quite understand what you mean when you say that 39.400 and 39.5200 are tower broadcasts of the 800mhz band. Are you telling me that MSP is transmitting on 800mhz?

And if so....why wouldn't I just be able to pick them up on the appropriate 800mhz freq?

I can pick up the MSP simulcast from frederick on the Frederick Co trunk system...I understand that, but taking that into consideration, that doesn't explain to me why I can't hear Rockville since they are Simulcast on Mont Co's digital 800 system.

 

[Al42]

Paul, clearly on the 154.16 issue, you are getting overloaded. A FM trap won't help you here ... And a shorted stub might be too lossy on other frequencies

A tuned 300 ohm suckout stub would be pretty narrow. Cheap enough to experiment with too - just a T connector, a piece of twinlead and some aluminum foil. Start about 40 inches long - wrap the foil around the end of the wire and start moving it up until the signal starts going down. It should null out at around 29 inches, depending on the velocity factor of the wire and the length of the path in the T connector. (Connect the scanner, the antenna and the trap to the T connector.)