Hello All,

We bought a kenwood repeater TKR-750 and 2 diamond F23 antennas plus
the programming software.

Unfortunately we can't hear anything beyond one kilometer. Here are the
frequencies we are using:

TX 15900
RX 16000
TONE1413

The equipment are being used in africa in a remote location for an NGO
helping refugees I am back here in the states now.

I would appreciate any pointers from the group.

Thanks.

- Nur

Nur;
Here are some thoughts. I am not familiar with the inner workings of the
TKR-750 so the first suggestion might be moot.

1. Make sure the receiver and transmitter are tuned to the operating
frequency. Some radios need tuning in addition to the settings of the
programming software. Tuning involves peaking filters inside the radio
for the operating frequency. This is not a do it yourself task. See last
suggestion.

2. Make sure the mobile units are tuned and programmed to the reverse of
the repeater frequency pair. It is common to have a second channel
programmed as simplex or "talk around" on the mobile units to permit
direct communications when out of range of the repeater. Usually this is
the same frequency as the repeater transmitter. Make sure the mobile
units are transmitting through the repeater.

3. It appears your repeater has a 1 MHz offset between transmit and
receive frequencies. No mention is made of a duplexer or any type of
bandpass filtering. The use of separate antennas does not assure that
the receiver will not be overloaded by the transmitter carrier or be
blocked by transmitter noise. Disable the transmitter or terminate it
into a proper dummy load and check to see if the receiver can now
receive at a longer range. If so you have "desense" and you need to pay
close attention to your antenna system, maintain TX and RX antenna
isolation, use double shielded cabling, use proper connectors and
provide proper duplex filtering.

4. You might have localized interference. See last suggestion.

5. Are you using portable radios? Is the terrain rough? Is the repeater
antenna system mounted low with respect to average terrain? If so you
probably are getting all the range you might expect (after exhausting
sugesstions above).

6. Hire an experienced radio man (or radio woman) to design install and
optimize the system. Buying parts and boxes will not assure success of
such a system.

Joe Leikhim
The RFI-EMI-GUY

wrote:

Hello All,

We bought a kenwood repeater TKR-750 and 2 diamond F23 antennas plus
the programming software.

Unfortunately we can't hear anything beyond one kilometer. Here are the
frequencies we are using:

TX 15900
RX 16000
TONE1413

The equipment are being used in africa in a remote location for an NGO
helping refugees I am back here in the states now.

I would appreciate any pointers from the group.

Thanks.

- Nur




--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"

The Lost Deep Thoughts By: Jack Handey
Before a mad scientist goes mad, there's probably a time
when he's only partially mad. And this is the time when he's
going to throw his best parties.