BCD436HP Antenna issues

[Constable1212]

I purchased a BCD436HP to get back into the scanner hobby. After reading some recommendations on antennas I bought a Diamond RH77CA. When it arrived I excitedly put it on and was suddenly not excited, as I was not getting any better reception. In fact the scanner stopped receiving the weather channels (162.*** range) which I could receive without any antenna attached as well as with the supplied rubber ducky. I can picked up all my local stations as well as Massachusetts State Trunking system with the supplied rubber ducky, so the radio has very good reception with the supplied antenna. But I always want to see if I can pull in further stations, especially aircraft. So I bit the bullet and bought a Diamond D-130J Discone Antenna. I currently have it in my loft and going to put in my attic as I have HOA to deal with. The weird thing it does the same thing. I get no weather channels when it is attached to my scanner and I get one station a little stronger, 2 bars instead of 1 bar with supplied antenna. Am I expecting too much, or am I doing something wrong? Why would it get the weather with no antenna and no weather with Discone antenna? Stumped! I mostly listen to public safety and aircraft on the VHF and UHF.

 

[Ubbe]

In fact the scanner stopped receiving the weather channels (162.*** range) which I could receive without any antenna attached...

That's the problem. The weather channels are too strong for the receiver and it gets blocked. One solution to that are to get a notch filter for that 162MHz range from PAR electronics. But then that transmitter are probably not the only one in that tower and you could have the same problem from other transmitted frequencies from the same nearby tower.

It's almost like a simulcast problem, you'll need the antenna to receive a less signal level to keep it below where the scanner stops being blocked.

Try using the attenuator enabled to frequencies in the 137-225MHz band to help with that particular 162MHz problem.

The discone probably needs a FM trap filter anyway, so get one for that first as it is the sum of all signals that matter and a FM broadcast filter might help at least with the discone.

/Ubbe

 

[Constable1212]

Thanks for the reply, not being antenna savvy, I would have never thought about the antenna making the signal too strong. Go figure.

 

[StoliRaz]

Sounds like you're from Massachusetts like me. Just FYI all of the weather channels fed from the Norton Ma NWS station were recently down for a while, that could also be why you heard nothing. Welcome to the board

Here's a thread about it over at SNE:

Scan New England - Login

 

[Constable1212]

Thanks, I’ll check it out. In my case there was a signal because when I disconnected the Discone antenna I could hear the weather. But when I reconnected the antenna the broadcast would stop.

Yes I am from Massachusetts and not to far from Norton.

 

[StoliRaz]

Thanks, I’ll check it out. In my case there was a signal because when I disconnected the Discone antenna I could hear the weather. But when I reconnected the antenna the broadcast would stop.

Yes I am from Massachusetts and not to far from Norton.

I see, I've experienced poor reception with 162.475 (Blue Hill) sometimes myself. I think it's geography sometimes as well, Moose Hill in Sharon is right in the way of us and Blue Hill and the Needham towers so my TV reception of Boston stations isn't good either. Then sometimes depending on the antenna I'm using I've pulled in the Pack Monadnock (NH) station 70 miles away with 2-3 bars of reception.

And me too, about a half mile from Norton 🙂

 

[WA0CBW]

Have you checked the coax for opens or shorts?
BB

 

[Constable1212]

I see, I've experienced poor reception with 162.475 (Blue Hill) sometimes myself. I think it's geography sometimes as well, Moose Hill in Sharon is right in the way of us and Blue Hill and the Needham towers so my TV reception of Boston stations isn't good either. Then sometimes depending on the antenna I'm using I've pulled in the Pack Monadnock (NH) station 70 miles away with 2-3 bars of reception.

And me too, about a half mile from Norton 🙂

Thanks for the reply. I guess I am in a pretty good area because I can pretty much pick up everything I want with the rubber ducky. I was thinking of returning the Discone, but since I fell off the ladder putting it up in the attic I think I'll leave it there. LOL Someone mentioned an FM trap, do you know if that would interfere with the aircraft frequencies? I would like to pick up Norwood Airport Tower. I am about 8 miles west of Norton.

 

[Constable1212]

Have you checked the coax for opens or shorts?
BB

I'll give that a try.

Thanks

 

[StoliRaz]

Thanks for the reply. I guess I am in a pretty good area because I can pretty much pick up everything I want with the rubber ducky. I was thinking of returning the Discone, but since I fell off the ladder putting it up in the attic I think I'll leave it there. LOL Someone mentioned an FM trap, do you know if that would interfere with the aircraft frequencies? I would like to pick up Norwood Airport Tower. I am about 8 miles west of Norton.

TBH I have no experience using FM traps, but locally Scannermaster in Holliston could probably point you in the right direction. They sell a bunch of different ones.

 

[Ubbe]

Nooelec has a good one that are also on Amazon. It can go directly on the antenna connector. Nooelec - Distill:FM Barebones - Broadcast FM Bandstop Filter for Software Defined Radio Applications - Other RF Blocks - SDR Addons - Software Defined Radio

/Ubbe