Realistic Pro-2021 external antenna

[jmatonis]

Recently, I received a Pro-2021 off of Ebay. The radio did not come with the whip antenna that sticks out the top. I replaced the external antenna connectors with a chassis mount BNC. I notice that when I connect the external antenna to the radio it attenuates the signal. If I just use an 18" piece of copper the signal is much stronger. I built a ground plane antenna for the 159Mhz band and the SWR are low 1:1. I was hope someone could offer some suggestions. It's as if the antenna is loading down the receive circuit.


Thank you

 

[Wackyracer]

Check your connections on your work or the antenna may be shorted to ground.

 

[cmdrwill]

Or the coax cable may be shorted or broken.

 

[Ubbe]

Isn't the 2021 one of the worst scanners when it comes to overload and de-sense issues? I would guess that you get too much signal from your excellent antenna that would de-sense the scanner. Try to use the attenuator function to verify that and then you could probably solve that problem by using a FM broadcast filter.
Amazon.com: fm broadcast filter

/Ubbe

 

[krokus]

Recently, I received a Pro-2021 off of Ebay. The radio did not come with the whip antenna that sticks out the top. I replaced the external antenna connectors with a chassis mount BNC. I notice that when I connect the external antenna to the radio it attenuates the signal. If I just use an 18" piece of copper the signal is much stronger. I built a ground plane antenna for the 159Mhz band and the SWR are low 1:1. I was hope someone could offer some suggestions. It's as if the antenna is loading down the receive circuit.


Thank you

Most likely, the receiver is getting too much signal, and dealing with desense issues.

Sent using Tapatalk

 

[TailGator911]

My 2021 is warehoused for that very reason. It doesn't play well with others. Stacked with other scanners on my desk it suffered from intermod and front end overload. It performed very well all alone in the kitchen so that's where it went until I replaced it. Great radio in it's day.

Years ago, I had mine hooked up to a rooftop discone and it performed great. That was out in the country. When I moved to Clearwater, FL (Tampa Bay area) that is when it started with the overload. I used the right-angle telescopic antenna in the kitchen and it worked well.

JD
kf4anc