VERY IMPORTANT INFORMATION CONCERNING WB4GBI/R 927.725 Mhz!!

VERY IMPORTANT INFORMATION FOR WB4GBI/R 927.725 USERS!!

 

As of Wednesday, April 19^th, 2012, the WB4GBI 900 Mhz repeater is now on 927.0625 Mhz, with a PL access of 151.4 Hz. Why did this happen? As those of you with 900 Mhz radios already know, my 900 Mhz repeater was not working well at all. Even the strongest of signals were experiencing "arcing" and noise as they transmitted thru the repeater. I was finally able to spend some time at the repeater site (the same site as 146.94 and 444.300) and troubleshoot the problem.

 

Kevin, W4KEV, has already placed his 900 Mhz repeater on the air from Sharp's Ridge in the center of Knoxville. When he did so, he experienced noise and interference problems as well. What he discovered was the same information that I used when troubleshooting mine. The 900 Mhz band is a "shared" band, meaning there are lots of other services, licensed and unlicensed, that are in the same "neighborhood" as we are. Some of those services are "spread spectrum," meaning that they emit an RF signal over a broad range of frequencies.  This includes hospitals, some cordless phones, fixed links (ever wonder about all those yagi antennae on traffic light control systems?),  and remote meter-reading devices used by electric utilities, etc. Kevin discovered that the 900 Mhz spectrum was littered with this kind of noise at his site above 927.100 Mhz (remember I was on 927.725).

 

After checking the repeater thoroughly for "desense" and antenna problems, and finding none, I decided to re-program the Motorola Quantar repeater and give it a try. The results are REMARKABLE. Users who were constantly noisy and hard to copy were quiet. Even when users are less than fully quieted into the repeater, they were not "arcing" as they were before. The data burst noise that appeared in the repeater at regular intervals is GONE. Finally, I can be proud of how the repeater is performing.

 

Lastly, Kevin has installed a link radio that has our two 900 Mhz repeaters linked together. So far, it seems to be doing very well.

 

For those of you who have one of the Motorola MCS2000 radios that were purchased recently, you can find my new frequency by selecting "ATL 0625"  in the first zone of programming. There is a repeater in downtown Atlanta that is on this same frequency and PL tone. I picked this frequency and tone combination on purpose, as it is already in the MCS2000 radios that I have programmed. This is one channel above the "NFARL" channel that Kevin's repeater is on. Or, you can contact me and I will make arrangements to re-program your radio for you.

 

I have just received notification that my coordination request for the frequency change was approved by SERA.  Thanks to Mike Bishop, WM4RB, for his quick response.

 

And on a final note, while at the repeater site, after taking care of a couple of matters for the " Frog," (that's the nickname of the radio station whose tower we share), I was also able to complete some work on the 146.94 repeater which removed the FM broadcast audio from the repeater audio. Now I know some will be disappointed that they can no longer hear the faint country music on 146.94, They can tune to 107.7 and hear it for real J.

 

I have the 53.150 Mhz antenna in hand, and will be installing it post haste! Get your six meter radio ready!

 

73 de Tim WB4GBI

 

Tim Berry

 

***PLEASE NOTE NEW EMAIL ADDRESS!!!***

tim.berry@cumulus.com

 

Tim Berry WB4GBI

Chief Engineer

Cumulus Media-Knoxville

WIVK-FM   WNML  AM/FM   WNRX-FM  WOKI-FM

OFFICE: 865-212-4519 (leave a message, I will be paged)

FAX: 865-909-0821

check out my website at www.wb4gbi.com

 

Chief Engineer

Vol Radio Network

IMG College/University of Tennessee

 

Tim Berry
timb447457@aol.com