Thanks, I’ve spoken with Par Electronics who makes custom notch filters, he can put something together for me. I’ve been listening this morning with attenuation turned on on the scanner and a lower gain antenna I installed yesterday, and I’m actually picking up the missing frequency now. I just need to see if I’m now missing anything else because of the attenuator.
Sudden Loss of Reception
- Thread starter emsflyer84
- Start date
ecps92
Member
Only you, experimenting, will actually know what might help you with your reception issue.
I've seen folks resolve reception issue with something as simple/odd as a Paper Clip
I've also seen folks resolve reception issues with true identification of the source/Freq causing the issue and installing filters in line, which then has caused them issues when they wanted to listen to something else.
As this is a hobby and many listen to a wide swath of spectrum, keep experimenting. And as pointed (I think by you) out that Height might have been the cause, so going lower or even (paper clip) might help for that ONE agency you want to hear.
Also, not being too familiar with that model radio, see if it can do ATT on that FREQ Only, Don't ATT everything only that one Freq
Yes, still experimenting. Yesterday I put a Motorola commercial mobile antenna on a ground plane kit on the roof in place of the Diamond X50. It's a short antenna, only like 20' tall. I'm very surprised at the good reception and sound quality. I guess I shouldn't be considering the quality of the antenna. So, I turned on the attenuator and this morning I actually heard some transmissions on the frequency I've been missing. Then some were still broken like before. I'm moving in the right direction.
Side note - I took my handheld BCD436HP on the roof with me yesterday and the signal I'm trying to pick up again came in crystal clear on the handheld with stubby antenna! So, maybe even a smaller antenna is what I need. I'm just trying not to loose other distant frequencies in the process.....
Or they're new to you, not many new VHF paging sites popping up these days. Moar antenna, moar signal, and in your case...moar problems.
Thanks, possible it's just confusing because I didn't change anything on my end and just stopped receiving the distant signals that I had been getting.
ecps92
Member
Correct
No new licenses, No pending licenses for both common VHF paging.
ecps92
Member
some other transmitter is causing you to hear those paging channels.
Could be almost anything mixing with the signals from FM Radio, NWS... all we can for from afar is throw the spit at the wall , while you take/try each suggestion which may/maynot work and might cause issues with something else you want to listen to
this you?
and then,
you sure as hell did change something. You have 3 or 4 threads regarding this issue since the new year, and these few are from the first post in it.
Yes. I mean I didn't change anything BEFORE the loss in signal. Then I made those changes above to try and improve things but it didn't work.this you?
and then,
you sure as hell did change something. You have 3 or 4 threads regarding this issue since the new year, and these few are from the first post in it.
Hang with me here, let me see if I have this right. I'm going to try to tl:dr your 3+ threads so we can address this developing XY problem.
First issue you ever brought up was you lost a VHF PD frequency that you never got really well. You replaced your feedline with LMR-400, shortened up your run, and went direct from antenna to scanner - to replace what used to be a CATV/splitter/in-wall/homejobber spaghetti mess. You are now getting VHF paging signals that you didn't get before. Those signals are affecting your device in a deleterious manner.
am I right to this point?
First issue you ever brought up was you lost a VHF PD frequency that you never got really well. You replaced your feedline with LMR-400, shortened up your run, and went direct from antenna to scanner - to replace what used to be a CATV/splitter/in-wall/homejobber spaghetti mess. You are now getting VHF paging signals that you didn't get before. Those signals are affecting your device in a deleterious manner.
am I right to this point?
Thank you. To clarify I never knew to look for the pager interference before so I don't know if I was picking up the pager signals before or not. All I know is I used to receive this one particular frequency and now I don't. But I DO in my car in the driveway. Ruled out interference by killing all power to my house with no improvement in reception.
Now, I'm not actually hearing pager noise in anything that I'm scanning. The only reason I started looking for pager signals is because I did an interference test where I manually tuned my scanner to the frequency I'm TRYING to receive, opened the squelch all the way and was seeing 3-5 signal bars along with the normal squelch noise, telling me there was a signal of some kind getting through. I could also hear a faint digital "pager" noise in the static, sounded like an office phone ringing or something. That's what tipped me off to start scanning for pager noise.
Then I found these:
So, based on all this info, I'm making an educated guess that these strong signals are interfering with the weaker ones I'm trying to pick up.
no problem.
Usually moar signals is moar bettar, but not in your case.
So yesterday I took my handheld scanner to the roof and stood next to my rooftop antenna. The handheld scanner was picking up the frequency I'm trying to get. Maybe small antenna with less gain not being affected by the pagers? So anyway, I know I CAN receive the frequency I want at my house. Something about my base scanner setup is killing the signal. Again, I've ruled out interference from my house itself, and basically ruled out feed line issues because that's all new.
Your rooftop antenna is likely a better antenna than any stubby. It's trying to pull in everything. Your old wiring disaster was attenuating that signal for you. You replaced that with new hotness. The new hotness is now taking all that signal and piping it to your scanner. Your old wiring actually helped you in that regard. Your scanner does not like that. The stubby antenna recieves less than the rooftop, even when right next to it. The scanner can handle the signal you are putting in it from the stubby.
The feedline is likely the issue. Issues can be good. Your improvements had unintended side effects. Your side effect is now your scanner is getting way more signal across the spectrum that it used to.
For gits and shiggles, attach the stubby to your base scanner and take it up on the roof. See what happens.
The feedline is likely the issue. Issues can be good. Your improvements had unintended side effects. Your side effect is now your scanner is getting way more signal across the spectrum that it used to.
For gits and shiggles, attach the stubby to your base scanner and take it up on the roof. See what happens.
I agree with this assessment. Now I play the game of "dumbing down" my antenna to balance out the better feed line and hopefully not loose too much in the process. Or go back to RG6 or something for the feed line. It's only about a 30' run.
Thanks for talking through this. If this is in fact my problem. I assume I have the following options:
1) Smaller, less-gain antenna
2) Lesser feed line (RG58, etc)
3) Notch filters for the offending frequencies
Or a combination of the above..... Does that make sense? Thanks.
1) smartest, cheapest first step. What kind of antenna connection do you have? -259 series?
2) last thing I'd try due to work involved.
3) most expensive, only if all else fails.
I have PL259 connectors at each end of my coax. Right now I have an NMO ground plane kit on the roof, so I can try anything with NMO or PL259 for antenna's
if you have a PL259 - SO259 adapter, you can just stick a piece of copper (6 inches or so) ground wire in the female end of the plug. That's the closest thing to a 800mhz 1/4 wave mini whip going. You could try longer wire after that, but the longer you get the better that VHF is going to come down the wire.
If that works and solves your excess signal problem, you can buy a 800mhz NMO 1/4 wave miniwhip on the ebays for under a tenner.
Ubbe
Member
It could be a mirror of a pager frequency you are getting, but could also be an overload issue but the 996 has a much better receiver than a 436 so are unlikely. On the frequency you have issues with to receive you make a Hold and then do Function+7 to enable IFX. It will change what mirror frequencies your receiving.
I always recommend to use a variable attenuator when using external antennas to more easy figure out whats going on. You gradually add attenuation to see how the signal you want to receive reacts and what the interference are doing. Scannermaster has one and you can also use the ones with F connectors if you get adapters or pigtails to go with it. With an overload issue the interference will be reduced much more than the wanted signal when slowly adding attenuation. You will also be able to listen to a weak signal and add attenution to see if the signal improves, that indicates overload, and you can leave that attenuation in place.
I would like to see scanners using several antenna inputs. As it is now all bandpass frequency bands are joined together using switch diodes to one common antenna connector. It would not cost much to have two or three antenna jacks and the switch diodes controlled to have each frequency or group/department/site directing a bandpass filter to a specific antenna connector.
/Ubbe
I always recommend to use a variable attenuator when using external antennas to more easy figure out whats going on. You gradually add attenuation to see how the signal you want to receive reacts and what the interference are doing. Scannermaster has one and you can also use the ones with F connectors if you get adapters or pigtails to go with it. With an overload issue the interference will be reduced much more than the wanted signal when slowly adding attenuation. You will also be able to listen to a weak signal and add attenution to see if the signal improves, that indicates overload, and you can leave that attenuation in place.
I would like to see scanners using several antenna inputs. As it is now all bandpass frequency bands are joined together using switch diodes to one common antenna connector. It would not cost much to have two or three antenna jacks and the switch diodes controlled to have each frequency or group/department/site directing a bandpass filter to a specific antenna connector.
/Ubbe
