[Alexandria Radio Club Reflector] 927.600 MHz Repeater Operational

Arnal arnalcc at comcast.net
Mon Nov 8 23:01:53 EST 2010 


Tim, 



     Thank you so much for all your work on the Repeaters, and the new 900 MHz Repeater.  As a former VHF and UHF Commercial Repeater Design Engineer, I know what it can take to get a system up and operating well. 



     With that in mind, I did some empirical testing this morning and tonight with Ted (W9TCE) coming back from burgers at Shooter Mc Gee's.  I have a 7" vertical dipole rubber duck on my handheld GTX-900 radio.  I do not know what Ted has on his. 



     I live in Rosslyn (100 yds north of the Iwo Jima Memorial)   I could not raise the 900 MHz Repeater from my apartment parking spot, standing outside my car with a clear view to the NE over DC.  I know that is not the direction of our Repeater, but as a reference test, I can and did raise the Ashton, MD 900 MHz Repeater.  WA3KOK (Trustee) advised me they have a satellite receiver in NW DC.  



     My drive to work takes me  past the east side of the Pentagon to Crystal City.   I could not raise our Repeater at any point on that drive from the handheld inside the car.  I park at a covered garage at the Reagan airport fly-overs from US 1 in Crystal City.  From the open-air south side on the second or third deck I could not raise the Repeater, from inside my car.  No test was made from outside my car.  



     Tonight while traveling to Burgers, at about King St and Quaker Ave, I had no problem raising the Repeater and received it full quieting.  Unfortunately, everyone else on at that point had forgotten their 900 MHz radios. 



     Upon arrival at Shooter Mc Gees (5236 Duke St), I could intermittently raise our 900 MHz Repeater from the parking lot, but not from inside. 



     Ted and I tested our handhelds from inside our cars driving home (him south towards Telegraph road (right, Ted??) and I going north on I-395.  Both Ted and I reported each other as "noisy, tough to make out the words" from the immediate vicinity of Mc Gees.  As I drove north of Seminary Road, Ted reported I was full quieting.  Ted came in stronger while he was stationary dropping off Ian.  I do not know if he was in or out of his car.  As Ted continued south, he remained weak. 



     By the time I got along the west side of the Pentagon, I was unable to key the Repeater.  The last I was able to key it from inside my car was 

 Glebe Rd and I-395. 



     I could hear Ian (N8IK) testing as I drove into my apartment complex to my parking spot.  I attempted to raise the Repeater using my car's roof as a ground plane (radio placed on it, no connection), but could not.  



     I moved to the second-story top (open air) tier of the parking garage (I park outside the parking garage for my HF antenna).  Using the metal flashing on the chest-high wall, I could not raise the 900 MHz Repeater.  I could raise the VHF .315 on a handheld sitting right next to it. 



     I did notice that my green "receive" LED was flashing continuously at that spot.  There is no "squelch off" button I could find, but momentarily when switching channels, a burst of intermod could be heard.  Moving to the simplex channel 1 (-100 kHz), carrier squelch, it was full of highly distorted audio and intermod or harmonic voice traffic, continuously (as in Broadcast audio).  103.066 MHz x9.  I am not receiving an FM broadcaster on either 103.1 or 102.9 MHz on my broadcast receiver in my apartment. 



     So far, this is as much as I can do to help.  Hope it does. 





Arnal, N9ACC 

----- Original Message ----- 
From: "timo 53" <timo_53 at juno.com> 
To: alexandriaradioclub at mailman.qth.net 
Sent: Sunday, November 7, 2010 4:46:45 PM 
Subject: [Alexandria Radio Club Reflector] 927.600 MHz Repeater Operational 

The new 900 MHz repeater is on the air. 

Output is 927.600 MHz  and the input is down 25 MHz at 902.600 MHz with 
PL of 107.2 Hz. 

The Motorola MSF-5000 repeater is currently configured in stand alone 
mode and cannot yet be cross linked to the other repeaters yet. 

Two vertically separated antennas are used rather than a duplexer for 
isolation.   The higher antenna is used for the receiver and has a mast 
mounted pre-amp with a notch filter.   The bottom antenna is used for the 
transmitter. 

Please give it a try if you have 900 MHz equipment.  Additional 
improvements and troubleshooting are anticipated. 

Tim 
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 Glebe Rd and I-395. 



     I could hear Ian (N8IK) testing as I drove into my apartment complex to my parking spot.  I attempted to raise the Repeater using my car's roof as a ground plane (radio placed on it, no connection), but could not.  



     I moved to the second-story top (open air) tier of the parking garage (I park outside the parking garage for my HF antenna).  Using the metal flashing on the chest-high wall, I could not raise the 900 MHz Repeater.  I could raise the VHF .315 on a handheld sitting right next to it. 



     I did notice that my green "receive" LED was flashing continuously at that spot.  There is no "squelch off" button I could find, but momentarily when switching channels, a burst of intermod could be heard.  Moving to the simplex channel 1 (-100 kHz), carrier squelch, it was full of highly distorted audio and intermod or harmonic voice traffic, continuously (as in Broadcast audio).  103.066 MHz x9.  I am not receiving an FM broadcaster on either 103.1 or 102.9 MHz on my broadcast receiver in my apartment. 



     So far, this is as much as I can do to help.  Hope it does. 





Arnal, N9ACC 

----- Original Message ----- 
From: "timo 53" <timo_53 at juno.com> 
To: alexandriaradioclub at mailman.qth.net 
Sent: Sunday, November 7, 2010 4:46:45 PM 
Subject: [Alexandria Radio Club Reflector] 927.600 MHz Repeater Operational 

The new 900 MHz repeater is on the air. 

Output is 927.600 MHz  and the input is down 25 MHz at 902.600 MHz with 
PL of 107.2 Hz. 

The Motorola MSF-5000 repeater is currently configured in stand alone 
mode and cannot yet be cross linked to the other repeaters yet. 

Two vertically separated antennas are used rather than a duplexer for 
isolation.   The higher antenna is used for the receiver and has a mast 
mounted pre-amp with a notch filter.   The bottom antenna is used for the 
transmitter. 

Please give it a try if you have 900 MHz equipment.  Additional 
improvements and troubleshooting are anticipated. 

Tim 
______________________________________________________________ 
AlexandriaRadioClub mailing list 
Home: http://mailman.qth.net/mailman/listinfo/alexandriaradioclub 
Help: http://mailman.qth.net/mmfaq.htm 
Post: mailto:AlexandriaRadioClub at mailman.qth.net 

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Please help support this email list: http://www.qsl.net/donate.html

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