HP-2: HP2 P25 Problem Headphone Port

[Guccisock5]

I'm using the HP2 for a broadcastify feed. One of the systems I monitor is bell fleetnet zone 2. I'm using the Headphone jack into the line in on laptop, works fine from a quality perspective.

However, whenever it's connected I cannot pick up fleetnet consistently! As soon as I disconnect, I pick up everything. All other frequencies are receiving fine.

At first I thought it was the laptop. It's about 6 feet away from the antenna now.

I'm really baffled as to how this could happen.

Thanks in advance

 

[Aviator747]

Is it the same if the laptop is running off battery compared to ac adapter? Possible ground loop?

 

[Guccisock5]

Is it the same if the laptop is running off battery compared to ac adapter? Possible ground loop?

It has been plugged in. I tried unplugging it for a while to see if it had an impact and it didn't

 

[djmorgan]

In the real old days the wire from the headset would also act as additional antenna source creating a diversity receiver, believe it or not. On our old old police system we had some scanners in dispatch and the headphone wire was sometimes just the right length to resonate on some frequencies, or so Motorola told us at the time. I would have though that that would have disappeared with modern radio designs. It may not effect other frequencies because it is not the right length or the signal strength is different. Probably has absolutely nothing to do with it but kind of an interesting idea.

 

[Guccisock5]

In the real old days the wire from the headset would also act as additional antenna source creating a diversity receiver, believe it or not. On our old old police system we had some scanners in dispatch and the headphone wire was sometimes just the right length to resonate on some frequencies, or so Motorola told us at the time. I would have though that that would have disappeared with modern radio designs. It may not effect other frequencies because it is not the right length or the signal strength is different. Probably has absolutely nothing to do with it but kind of an interesting idea.

Interesting, I can see that happening.

I have a 3 ft cable and a 6 footer I bought to move the laptop far enough away from the antenna but they both have the same effect of blocking p25.

 

[JoeBearcat]

Do you have a Bluetooth adapter set you can try to isolate the grounds from each other? It could be noise on the ground of the PC affecting the reception?

Also, are you using a mono or stereo cable?

 

[Guccisock5]

Do you have a Bluetooth adapter set you can try to isolate the grounds from each other? It could be noise on the ground of the PC affecting the reception?

Also, are you using a mono or stereo cable?

I won't be able to try until the weekend but I'd bet that's the case.

If confirmed, is there any way to fix this?

 

[mc48]

Try a ground loop isolator they cost around $10-15 on Amazon.

 

[Guccisock5]

Update, I'm now getting interference when plugged into the wall with USB. Is it possible there is something internally wrong with my unit?