Feb. 17, 2007
These Pictures
Were Taken When We Went Over
To Reinstall The Motorola RF Amp Back On The D-Star Repeater A Few Days After The Big Snow
!
We Only Got Stuck 4 Times Getting Back To The Building !!
* * * I Guess We Should Have Known Better * * *
Mar. 3, 2007
Pictures Taken The Day We Decided To Do Some Testing Of The Digital Repeater After The Installation Of The Rebuilt TE Systems Power Amp We Installed A Few Days Earlier Since The Motorola Amp Installed On February 17th Didn't Work Out. We Wanted To Get A Better Understanding Of The Repeater Operation, Find Out More About The Receiver Signal Required To Operate The Repeater, And Also Make Sure The Advanced Receiver Research Pre-Amp Was Working Properly.
The Room #1
The Room #2
The Test Equipment
Tool, Cables, Adaptors, Stuff !!
TE Systems PA Deck
Ready To Go To Work !
D-Star UHF Mod #1
D-Star UHF Mod #2
D-Star Back
D-Star Watt Meter (50W into feed-line)
Our New Digital Signal Generator #1
Our New Digital Signal Generator #2
Our New Digital Signal Generator #3
Back On The Air Testing
Our testing of the system with our fine new digital signal generator showed that the stock receiver required a -103dB (1.6uv) signal to activate the repeater.
With the addition of the Advanced Receiver Research receiver preamplifier and the 3 pass cavities we have had in the system, the repeater would then activate at -120dB (.23uv).
Even though this is quite a big improvement to the required receiver signal, this is still not what we would expect for our repeaters operation. All of the repeaters we have put on the air will operate with a signal more in the range of a -125dB (.13uv) signal level.
After scratching our heads and trying several other things to make more improvements to the signal required, there seemed to be nothing more we could fine to improve this situation. We feel the next step is to find how to change the internal setting of the receivers squelch via software if possible which might get us a few more dB.