Antenna Grounding Question

[prcguy]

The OP only needs to receive the 162MHz range for railroad comms. The Tram antenna he is considering will work many times better than the OmniX for RR.

If you're looking at a receive-only antenna, I've been reading good things about this one...

OmniX Scanner Base Antenna

 

[JoshuaHufford]

Yes, thanks for the suggestion but I don't want anything that wideband.

 

[mule1075]

Yes, thanks for the suggestion but I don't want anything that wideband.

TrainTenna Vertical Outdoor Base Antenna

 

[prcguy]

The Tram antenna he is considering will work many times better than the Traintenna for RR.

TrainTenna Vertical Outdoor Base Antenna

 

[JoshuaHufford]

The Tram antenna he is considering will work many times better than the Traintenna for RR.

I had considered the Traintenna but just looking at specs figured the other antenna I asked about would be better. Just curious why you feel it is better?

 

[prcguy]

The Traintenna is a single half wave element and probably just a Slim Jim type of J pole in a tube. The Tram antenna is three 5/8 wave elements in phase. The Tram will work much better and its not just a feeling.

I had considered the Traintenna but just looking at specs figured the other antenna I asked about would be better. Just curious why you feel it is better?

I had considered the Traintenna but just looking at specs figured the other antenna I asked about would be better. Just curious why you feel it is better?

 

[Ubbe]

They are also known to light up the coax with RF, meaning the outer braid of the coax becomes a radiating part of the antenna unless you apply proper RF choking at the feed point.

That's because it is a balanced feed point and if you connect an unbalanced coax to it you'll need to decouple the coax from the antenna with ferrit chokes or equal. A better way are to use a balun. The standard 300-75ohm can be used but you need to attach it to the jpole much higher up to reach the antennas 300 ohm point.

/Ubbe

 

[JoshuaHufford]

That's because it is a balanced feed point and if you connect an unbalanced coax to it you'll need to decouple the coax from the antenna with ferrit chokes or equal. A better way are to use a balun. The standard 300-75ohm can be used but you need to attach it to the jpole much higher up to reach the antennas 300 ohm point.

/Ubbe

Is this a problem if you only receive?

 

[Ubbe]

An antenna don't start to behave differently depending of if you transmit or receive, it performes exactly the same. Don't let anyone tell you differently. It still has the same SWR , gain and directivity, all the possible parameters for an antenna.

/Ubbe