Pro 107 With Discone Ant Poor Reception

Status
Not open for further replies.

MIKEEILEEN

Member
Premium Subscriber
Joined
Mar 30, 2010
Messages
4
Location
Sunrise, Fl. 33351
I have the RR Pro 107 hooked up to a discone antenna with 50 ft of RG8. I monitor the Ft Lauderdale International Airport Tower. I can hear the approching aircraft but not the tower. I have a RR Pro 2038
and i have no problem hearing the tower with the discone. Could the discone ant signal be over loading the front end causing it to de-sensitize ? Any help would be appreciated.

Thank You

Mike
 

Alliance01TX

Member
Premium Subscriber
Joined
May 11, 2007
Messages
301
Location
DFW Texas
Airport - Discone Antenna

Hi Mike:

A couple of thoughts / ideas to ponder.

First, a Scanner Discone type antenna generally has very low 'gain' as most (not all) are used in 'wide-band' configuration, allowing us to receive lots of freq's across the spectrum. So that's a key factor in many cases. Also, many Discone's (again not all) are situated in the 'horizontal plane' as reference to earth, so more on this later....

Next, you are getting aircraft Comm's (aircraft side) due to the height (above MSL) of the aircraft on approach or in transit at higher flight levels, etc...So they are basically "sending down-wards" if you will the signal, so you will almost always hear more Aircraft than a Tower or Approach /Departure Comm's.

The Tower(s) often have a much lower output power and are transmitting in the vertical plane (relative to earth) as are the Aircraft 'blade antenna' systems.

So what I would recommend is a few 'location test' with your gear to ensure the antenna, coax, connectors and radio are working. If the radio will work via 12-vdc car battery / adapter take it out to several areas around the airport and see what you can pick up on a busy weekend or or other time that has a lot of air traffic...etc...

Then, slowly work you way out-wards from the airport area, and see when you start losing the Tower or check if the Airport has an 'automatic terminal forecast' that is updated hourly / as required that transmits continuous. You will need to search the RRef database to get the proper freq(s) for ATIS or the like in your area if available.

As always, you might try another antenna, with a Vertical 'cut' to the 118~136 am range if that is a primary interest. The antenna at 1/4 wave should not be an issue and I have home-brewed using old Radio Shack CB antennas (no loading coil) and 'cut' them down to a desired freq range....

As always, double check the connectors, coax and such and hope this gives you a few ideas....

Thx

Bill
 

Alliance01TX

Member
Premium Subscriber
Joined
May 11, 2007
Messages
301
Location
DFW Texas
Ft Lauderdale Airport Freq'a

Mike

FYI here are the KFLL Airport Freq I show:

Radio communication frequencies for Fort Lauderdale Hollywood International Airport
APP: 118.1 MHz (MIAMI APP)
ATIS: 135 MHz
CLD: 128.4 MHz (CLNC DEL)
DEP: 119.7 MHz (MIAMI DEP)
GND: 121.4 MHz
TWR: 119.3 MHz
UNIC: 122.95 MHz (UNICOM)

All Freq's are in the 'am' modulation scheme and note that a couple of freq's are via Miami and they likely have 'remote' to the antennas for the APP/DEP....

Also see: Pilot information for Fort Lauderdale Hollywood International Airport @ OurAirports

Hope this helps.....

Thx

Bill
 

SOFA_KING

Member
Joined
Apr 25, 2004
Messages
1,581
Location
SE Florida
I think you missed his point...the 2038 works, so why not the PRO-107?

I have the RR Pro 107 hooked up to a discone antenna with 50 ft of RG8. I monitor the Ft Lauderdale International Airport Tower. I can hear the approching aircraft but not the tower. I have a RR Pro 2038
and i have no problem hearing the tower with the discone. Could the discone ant signal be over loading the front end causing it to de-sensitize ? Any help would be appreciated.

Thank You

Mike
A discone antenna is a great scanner antenna, and not many omni antennas will serve you as well. You might have an overload situation. My GRE made PRO106 and PRO197 scanners get hammered by FM broadcast transmitters. A cheap RS FM Trap (no longer sold by that useless store) cured all my VHF overload. That may be the real problem. Sunrise is an RF dense area. And those TV towers on the county line really generate allot of noise. Even my Motorola radios got hammered!

Try an FM Trap filter. It might do the trick.

Phil
 

kcoleman

Member
Joined
Jan 17, 2004
Messages
388
Location
Tallassee, AL
I agree with Sofa King on this to try a FM notch or trap filter. You might also add more squelch on the 107 to help out too. I've found that I don't get quite the same results on the 107 as I do my PSR-400 when connected to the same antenna. But then again they are different radios with different specs.

So, yes, you are probably seeing frontend overload and/or desense of the radio.

Good Luck,
Keith
 
Status
Not open for further replies.
Top