The AERIALS team members have started the effort to restore the 443 Repeater system to working order.
It is our plan to address all existing problems with the site first, replacing what is needed to get the system back into decent working operation with whatever components are available. Later we will completely rebuild the system with a repeater and other sub systems as required.
On our first visit to the site after taking ownership we found a number of problems with the system. To begin with there was less than two watts of RF power coming from the amplifier. We found a bad jumper cable, shot lightening arrestor and a power amplifier that was smoked probably by a combination of lightening and over heating. The deep cycle battery of the automatic backup power system was also shot.
The PL encode on the transmitter and the receiver pre-amp were also intermittent. The jumper bad jumper cables and lightening arrestor were bypassed and the repeater controller was completely reprogrammed.
On our second visit to the site the system was diassembled and cleaned. All of the bad components were replaced and PL encode problem was corrected and a better but temporary A.C. cooling system was installed. The receive pre-amp was taken out of line as it was acting like an attenuator. This pre-amp needs to be tested and replaced in the near future as the receiver sensitivity alone is not good enough.
The system was put on a Motorola service monitor and checked for all paramenters including spectral purity. We discovered that the trasmitter was a few kilohertz off frequency and that the deviation was low. We then netted the transmit frequency and made other adjustments to improve system performance.
On our third visit to the system we again tested all parameters and then re-installed the receiver pre-amp. At that point tests were again made of the system with critical attention paid to the possibilty of desense and weak signal capture. We found the system to be performing up to expectations with stations now able to work into the repeater from as far away as Middletown while mobile with 5 watts and DFQ reception into the repeater and operation from Lakewood hand held with with less than 5 watts and rubber duckie antenna with 70-80% quieting in the repeater. [NOTE: On the following day I even had a QSO with April, KC2BIT on her way up the NJ Turnpike past Newark airport and up past Yankee stadium. This was NOT a DFQ QSO all the time she was driving, more like little QSOs now and then when she was in the clear, but it mobile from that distance is not bad and she was DFQ at time... ah a better antenna for the repeater and a hotter receiver, what then ?]
We then continued to monitor the sytsem for several hours with the specturm analyzer for a few hours to validate the cooling of the system and to make sure that the transmitter remained clean when heavly used and heated up and to check for the intermittant noise on the receiver.
Subsequent trips to the site will result duplexer re-cabling and retuning, a reworked D.C. wiring buss being installed, the installation of an improved emergency backup power system, the installation of a dbProducts DB-8800B-350 site monitor to check and display VSWR, forward and reflected power and trigger an on-the-air voice Alarm message when either the D.C. power supply fails or the transmission line system has a fault condition.
The system is now working much better with the temporay comfiguration what we have patched together. However a completely new repeater and continuous duty amplifier will be configured and installed in the near future for more stable and better perfromance.
Below are some photos taken during our work parties.
These first three photos represent the system before we did anything at all.
This is a photo of the repeater cabinet with both doors open. The deep cycle back up battery on the bottom of the cabinete can be seen.
In this photo a close up the Astron power supply with repeater, amplifier and duplexer can be seen.
This photo shows the rats nest of D.C. cabling which powered the repeater.
The following photos are of team members as work begins to clean and reconfigure the system.
This photo has N2CKH in a moment of deep thought regarding controller programming.
Here we have N2IHN and N2CKH discussing controller reprogramming with W2UG off (smart guy) camera taking the photos.
After our second work party the system started to look better (cleaner) and sound much better with the installation of a temporay amplifier based on a GE Master II mobile with additional cooling added. It is planned that the new repeater to be built will be Master II based with a rack mount continuous duty amplifier. Here are some shots of the system from the front:
Here is a shot from the front of the system with cabinet doors both open. The RC-96 controller (partially shielded with aluminum foil that may no longer be needed is below the Astron power supply. Next is a GE Master II that at present is only being used for its amplifier then on top of that is the GE Executive II being used as the exciter and receiver. Next is a rack mounted cooling system consisting of four A.C. powered muffing fans blowing down. Then the Wacom WP-678 duplexer and an additional Motorola receive pass cavity.
Here is the cabling from the GE Exec II exciter/receiver to the GE Master II amplifer as seen from the cabinet read..
Another view of the cabling from the GE Exec II exciter/receiver to the GE Master II amplifer as seen from the cabinet front..
A close of the GE Master II RF output cabling.
A close up of the Wacom duplexer and rack mounted cooling system.
Here are some shots of the system from the rear:
The D.C. power buss has been improved, however it needs to be completely redone as does the battery backup system.
The additional lightening arrestor in the cabinet between the duplexer and hardline.
A close up of the amplifier cooling system from behind.
Here is the ARR pre-amp which is MUCH needed on the GE Exec II receiver. Without this 17db gain pre-amp (19.5db gain measured) the receiver sucks.
To send us e-mail Click Here.
AERIALS, Inc.
U.S. Post Office Box 8
Morganville, N.J. 07751-0008