Joint Ocean Monmouth Amateur Repeater Linking System (JOMARLS)

-- Open Linking Policy --


JOMARLS is a concept, JOMARLS is not a club.

Click here to learn all about the JOMARLS concept

The repeater owners will maintain an "open repeater" policy. However some features and control of the link system will only be accessible on invitation or membership of the club sponsoring that particular repeaters point of access in a given geographic area.

All interested parties are welcomed to link their repeater systems to JOMARLS and experiment with our open systems features and bring their specific capabilities to the mix. All we ask is that the following technical guidelines are followed.


N2CKH Linking Hub Technical Guidelines

-- The following technical guidelines are subject to change --

1. All linking must be accomplished by use of an FM UHF linking radio tied to your repeater controller linking port via the N2CKH UHF (70cm) duplex linking hub under FCC Part §97.201 Auxiliary station. Cross band links or other methods to link to the N2CKH open repeaters will not be permitted without special temporary permission.

2. All users must apply to coordinate their link radio use of the linking hub frequencies regardless of what NJ county their repeater system is located within. For SNJ in Ocean county and further South and PA contact ARCC (http://www.arcc-inc.org/) and for Monmouth county and North contact MetroCor (http://www.qsl.net/metrocor

3. The UHF linking radio used must operate half duplex and must transmit the PL tone (or DCS code) assigned to access the N2CKH UHF Linking Hub when you request to link your system with the hub.

4. As the goal of the UHF linking hub is to repeat the incoming signal with minimal distortion and for the system to have balanced audio levels throughout, all linking radios MUST be setup for a 4.5 kHz deviation using a 1 volt p-p 1.0 kHz test tone with no PL during setup. Then remove the 1.0 khz test tone adjust the PL or DCS level for a 700 Hz deviation. The absolute worst case deviation shall not exceed 4.8Khz when modulated

5. The UHF linking hub transmitter will always transmit the same PL tone (not DCS) regardless of the coded signal it receives. Thus the linking radio used will need a separate decoder unless it supports dual code encode/decode or at your descretion you can run your link radio receiver in carrier squelch mode as long as no noise blows squelch. However, there may be special signalling on the hub at times using other PL and DCS selective calling that will be received in carrier squelch only operation.

6. Linking radios must use directional anatenna and the minimum amount of transmiter power needed for a reliable, full quieting signal into the N2CKH UHF linking hub. To the extent that the link radio used does not allow reducing power beyond a threshold that is the minimum recommended for the radio PA that an attenuator will be placed in line with the transmitter PA so that signals into the hub will not cause interference during non-coded CW ID transmittions.

7. Linking radios must NOT transmit any form of voice or CW ID, courtesy tones, tail messages, or any thing other than system receiver user audio over the link radio to the N2CKH UHF linking hub. Do to IRLP linking requirements this is a MUST.

To meet FCC Part §97.119 station identification requirements we ask that you transmit a CW (4-6 character callsign, no slash (/) or anthing else) ID ONLY. All such transmissions are to be kept to the absolute minimum and the CW ID must be sent at the maximum 20 WPM. The CW tone must be set below 300hz. If possible the PL or DCS signal should be dropped during these transmissions on the link radio and if possible RF power should be reduced during these transmissions as well.

Another method that the FCC may accept is to have all your users ID the link radio by using its callsign while they ID such as "N2XYC on the N2ZZZ link" every ten minutes during use.

8. When the link radio is activated at your Repeater site, the repeater receiver must operate with PL or DCS decode on RX at all times. Your Repeater must be configured so that the link is dropped automatically if your Repeater receiver is taken off PL or DCS decode.

9. Your link radio must have a 3 minute time out timer and a post activity time out for the link transceiver of 30 minutes or less when your local repeater activity goes quiet unless your link port is configured to a receive only monitor mode.

10. You must provide us the command codes to bring up and take down the link on your repeater to share with our control operators.

11. All users of your repeater must announce verbally when bringing up and taking down the link.

12. As the system can potentially be connected to the world wide, all users need to be educated to listen before making any transmissions to determine the current state of the system.

We recommend that GE/Ericsson Delta-S or Canadian Motorola Mitrek UHF low band (400-440Mhz) transceivers be used for the linking radio due to their proven design and inexpensive cost.


JOMARLS
is dedicated in the memory of
Santo (Sam) Ugliarolo, Jr. WB2HAE


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This site is and will always be under construction, since there is always room for improvement.

Entire contents Copyright © 1999-2001 by Stephen B. Hajducek, N2CKH. All Rights Reserved Worldwide.