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

Need more input. How far apart are the antennas horizontally and vertically?
What filters are you using on the receiver input? I am assuming you mean
159 and 160 MHz. My first guess would be desensing, but without additional
info, it is just that.

wrote in message
oups.com...
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

wrote in message
oups.com...
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.

It appears that you are buying hardware, and believe that this is "Plug and
Play" - WRONG.

You appear to lack and understanding of how to properly design a repeater
system. The equipment is EASY - proper design is the VALUE (and knowledge
required) to have an efficient overall repeater system.

A repeater system is completely DIFFERENT than a normal radio usage or
system - SINCE the transmitter and receiver are operating at the SAME TIME !

Since you have not mentioned the usage of a cavity filter (duplexer) for
this system OR the spacing of the antennas -- I assume that the transmitter
is "desensing" the repeater's receiver. (Think of it as you trying to hear
a distant friend when someone next to you is shouting -- that's what is
happening)

You MUST either user a 6 cavity or physically space the receiver and
transmit antennas sufficiently apart (horizontally or vertically) so that
the receiver is NOT desensed by the transmitter (at least 60 dB reduction of
the transmitter at the receiver's input.

The ARRL FM and Repeater book (1970s) covered this in detail.
The Repeater Builder's Web Site -- will likely be very instructional for you
http://www.repeater-builder.com/rbtip/

Here are the frequencies we are using:

Tx: 159.000 MHz
Rx: 160.000 MHz

I assume that these have been approved by the government body of the African
country you are operating within? If NOT, you better address this first, or
you may have addition issues. Definitely not an amateur radio frequency in
your ITU Region.

OK, you have 1 MHz spacing between the receiver and transmitter. This is
useful for your future calculation of how much isolation (dB) that you will
require.

CTCSS Frequency (sub-audible): 141.3 Hz

I edited your value - since I think you are saying you are using CTCSS at
this frequency. First get the system running without CTCSS enabled - THEN
you can worry about CTCSS

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.

Sit down and read and learn how to properly design a repeater system. I
know engineers who have been doing it for years -- that still have to work
on final system designs. Local terrain, coverage desired, antenna location
and height are all CRITICAL factors for a good design. You will should be
using accurate topology maps for the area.

Call or web site visit the Kenwood Land Mobile support department
(California) and ask for Technical Assistance.
http://www.kenwood.net/indexKenwood.cfm?


Thanks.

- Nur

Usually you would use ONE antenna for a repeater instead of 2 antennas
You need a duplexer (cavity filter) so the transmitter output won't get into
the receiver's input.
You have some research to do. It's not a simple 'normal' radio
installation.


wrote in message
oups.com...
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