Heading Down the Black Hole

[emsflyer84]

Hey guys,

I’ve got a TRX-1 from Whistler that I have set up to broadcast online. It’s working great. Here is my antenna situation. I started with one of those all-purpose / all-band PVC pipe home made deals from MaxxTenna on Ebay and 50’ of RG6 running to my roof. It worked well for what it was. There were some folks online who told me I was probably not getting peak performance from an antenna like that, and it was probably just a rubber duck or tin foil inside a pvc tube.

So, then came the upgrade. A Centerfire folded dipole tuned to VHF specifically. With a 300 to 75 ohm transistor. Same location, same cable.

Same performance... In fact, it seems like the dipole has more background noise and less clean audio being received. There was one frequency (digital vhf) that was being picked up with the MaxxTenna but the transmissions were not readable (digital distortion). I was hoping the new antenna would grab this frequency more clearly. It hasn’t yet. Same digital noise.

Now I’m looking again. I’m hoping someone can talk me off the ledge here. I live in a mountainous area and it’s possible that the one signal I’m looking for is a lost cause unless I have significantly more height. It’s possible that I am picking up everything I’m going to get at this point, regardless of the antenna.

So basically I’m just looking for general thoughts on the situation from others who have been in the same boat.

My antenna restrictions basically are that I have to be able to mount it on an existing 1” metal pole on my roof. And I’m trying to keep it as low profile as possible to keep the wife happy.

Believe it or not, I’m thinking about going back to the all-band homemade PVC thing!

Thanks guys.

 

[emsflyer84]

Well, after some more playing around with location, the reception with the dipole seems to be improved.

 

[ka3jjz]

Be more specific about where you are (town/city and county is fine- folks can look up your location in our db) and what is this one frequency you are trying to hear? ... Mike

 

[emsflyer84]

Hey there, I’m in Wolfeboro, NH in Carroll County. I was trying to listen to Conway PD, also in Carroll County. It’s strange, I won’t hear anything on their freq for days and they out of the blue I hear a few minutes of transmissions crystal clear, like we’re in the same town.

 

[jim202]

If your looking for anything to listen to, you might try the 2 meter ham band and the multitude of repeaters they have in your region. You can do a search on the Internet for sources such as the repeater book and other sources.

 

[emsflyer84]

Thanks, I'm actually working my my Amature license. We do have several active repeaters around here which is nice.

 

[WB9YBM]

So basically I’m just looking for general thoughts on the situation from others who have been in the same boat.

You haven't mentioned your feedline; have you checked the quality of that? If it's lossy, that could explain why antenna improvements don't show any great change.

 

[Ubbe]

I'm in a similar situation where a telescope antenna on a scanner gets my hardly anything to monitor. It's a huge difference for me going from a roof top 1/4 wave GP antenna to a vertical with a 9dB gain or a yagi with 13dB gain. Also using a low noise amplifier helps a lot, even when my coax has less than a 1dB loss. Even those low quality $10 CATV amplifiers made an improvement when I used my old crystal scanner in the 80's.

Not being able to receive any direct signals and only its reflections makes it extremly dependent of the wheather and time of year. Even when a nearby airplane pass by makes me hear signals that reflects from it that I normally do not hear.

To me in a weak signal situation at home makes antenna gain a very important factor.

/Ubbe

 

[emsflyer84]

Well guys, out of nowhere the frequency that wasn’t coming it at all or was only coming in digital before is working perfectly now. Like it’s right next door to my house.

I have no explanation. It’s like the scanner and antenna knew what I wanted to listen to. But it’s been several days now of clear transmissions. We’ll see if it keeps up.

 

[DeepBlue]

Discone antenna, outside or in the attic. Best starter solution for folks that aren't sure what they want to listen to.

2 examples:

Diamond D130J Diamond D-130NJ Discone Antenna

www.universal-radio.com

Diamond D220R Antenna, Diamond D-220R Scanner Antenna

Best of luck,
S

 

[DJ11DLN]

Well guys, out of nowhere the frequency that wasn’t coming it at all or was only coming in digital before is working perfectly now. Like it’s right next door to my house.

I have no explanation. It’s like the scanner and antenna knew what I wanted to listen to. But it’s been several days now of clear transmissions. We’ll see if it keeps up.

There could actually have been a problem with that station. Our instinct here is to start looking for problems with our equipment or programming when things twang out of tune but things do get out of whack on the other end sometimes.

 

[trentbob]

Well guys, out of nowhere the frequency that wasn’t coming it at all or was only coming in digital before is working perfectly now. Like it’s right next door to my house.

I have no explanation. It’s like the scanner and antenna knew what I wanted to listen to. But it’s been several days now of clear transmissions. We’ll see if it keeps up.

A lot of smart people here to help you, wish we knew what you were trying to listen to. Maybe I missed it

 

[WB9YBM]

I'm in a similar situation where a telescope antenna on a scanner gets my hardly anything to monitor. It's a huge difference for me going from a roof top 1/4 wave GP antenna to a vertical with a 9dB gain or a yagi with 13dB gain. Also using a low noise amplifier helps a lot, even when my coax has less than a 1dB loss. Even those low quality $10 CATV amplifiers made an improvement when I used my old crystal scanner in the 80's.

yeah, the telescopic antennas on the radios--at least for me--is just a "start-up" type of approach. For optimum reception the antennas still need to get outside away from the "ground clutter".

 

[emsflyer84]

Well, that same frequency now is coming in garbled, sounding “digital” again. I haven’t changed anything. Very strange. Sometimes it works for a few days, sometimes it doesn’t. Maybe it’s atmospheric. Who knows.

 

[trentbob]

So I've been curious what you been trying to listen to but I see you did give the town and state your trying to get and that's Conway Police in New Hampshire. That is a VHF High digital frequency as you had pointed out 155.64 NAC 317. It looks like all of your fire and police are VHF high but only the police dispatch in the different towns are digital. Fire and ambulance look like they're PL tone protected. How do they sound?

Your coax is okay even though it's a long feed because you're working with VHF and not UHF. Since all you have around you is VHF High you can go with a specifically tuned antenna for 155 megahertz. If I could suggest on your metal pole a VHF High ground plane. You can probably pick one up for 25 30 bucks. I think your wife could live with it. The GRE Whistler should be okay handling VHF High digital. I see Wolfeboro PD is VHF High digital also, I assume that doesn't have a digital sound.

So here's the big question. How far away are you from Conway? If it's a long distance and you're getting a crappy signal the first sign of that would be intermittent digital sound or no reception at all. Because it's digital it behaves differently than a normal PL tone protected VHF High frequency.

 

[ecps92]

What Freq/Tone are you using- be specific, so we know what you are actually programming for listening

Well, that same frequency now is coming in garbled, sounding “digital” again. I haven’t changed anything. Very strange. Sometimes it works for a few days, sometimes it doesn’t. Maybe it’s atmospheric. Who knows.

 

[emsflyer84]

Hey there, thanks for the info. I am quite a distance from Conway. As the crow flies, I'm just under 30 miles, but I don't know exactly where their transmitter site is. The analog VHF stuff (FD/EMS) in that area, dispatched by the Conway Police is very scratchy and almost not readable. So it's not surprising that the digital PD transmissions are coming in broken and "digital" sounding. It's just so confusing why sometimes they come in perfectly clear, like they're the same town. You're right on assuming the Wolfeboro digital PD transmissions come in clear as day here. And plenty of other digital transmissions from around the state come in clear as well.

It's almost like Conway was broadcasting from a different tower on those days when it was coming in clear. I also noticed that the weather was overcast at least a couple of those days, but I can't be sure about all of them.

The folded dipole I'm using is tuned for high VHF, but not 155 specifically.

 

[emsflyer84]

For ecps92:

155.64 NAC 317

 

[trentbob]

What Freq/Tone are you using- be specific, so we know what you are actually programming for listening

See my post number 15

 

[emsflyer84]

So I've been curious what you been trying to listen to but I see you did give the town and state your trying to get and that's Conway Police in New Hampshire. That is a VHF High digital frequency as you had pointed out 155.64 NAC 317. It looks like all of your fire and police are VHF high but only the police dispatch in the different towns are digital. Fire and ambulance look like they're PL tone protected. How do they sound?

Your coax is okay even though it's a long feed because you're working with VHF and not UHF. Since all you have around you is VHF High you can go with a specifically tuned antenna for 155 megahertz. If I could suggest on your metal pole a VHF High ground plane. You can probably pick one up for 25 30 bucks. I think your wife could live with it. The GRE Whistler should be okay handling VHF High digital. I see Wolfeboro PD is VHF High digital also, I assume that doesn't have a digital sound.

So here's the big question. How far away are you from Conway? If it's a long distance and you're getting a crappy signal the first sign of that would be intermittent digital sound or no reception at all. Because it's digital it behaves differently than a normal PL tone protected VHF High frequency.

Also, just for fun I ordered a ground plane kit that I will add my Diamond RH77CA which works very well on my second TRX-1. I'll mount it in the same location as the dipole and use the same cable, etc, to see what happens. I know this isn't a good long-term outdoor solution, but at least I'll know if I should be using a different type of antenna.

Another interesting point.... on one of the days that the Conway PD signal was coming in clear, I also picked them up from my house for just a few seconds using my second TRX-1 with that Diamond antenna, which has never happened before.