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UHF Net - November 7th

posted Oct 11, 2010, 4:37 PM by Charles Boling   [ updated Oct 23, 2010, 9:14 PM ]
Our November 7th net will be held on our established backup medium, LCARA's 70cm repeater, instead of the 2m.  Rick, KE7SKM, will be providing a 2m link for those that don't have UHF capability.  He's located in a favorable location in Ranier, so most people who can hit the normal repeater will be able to reach him.

Radio Setup
Main Repeater
  • Rx Frequency: 444.900 MHz
  • Tx Offset: +5 MHz (449.900 MHz)
  • Sub-audible Tone: 114.8 Hz
2m Simplex Link
  • Rx Frequency: 146.500 MHz (LV STK)
  • Tx Offset: none (146.500 MHz)
  • Sub-audible Tone: none
Rick's link will listen to the repeater on 444.9 MHz and transmit what it hears on 146.5 MHz -- unless it hears someone first on 146.5 MHz, in which case it will transmit what it hears there on 449.9 MHz so the repeater will pick it up.

What the experience will be like:

70cm repeater users
  • Just like...using a repeater!  You'll hear everyone (including 2m users) as normal.
  • If you're a hill or three away from the repeater, you may find that you can't hit it quite as well as you do on 2m.  Two possible reasons for this:
1. Higher frequencies don't "bend" as much
2. Some radios put out less power on UHF (e.g. 35W vs. 50W)

2m simplex users
  • You'll receive 70cm users equally strong. (Quality will, of course, depend on how well they hit the 70cm repeater.)
  • You'll receive your fellow 2m users simplex, so you may not hear some of them.
  • You may not always see/hear the repeater "tail" at the end of your transmission; it must be long enough to cause Rick's rig to relay it (see the note below on repeater delay).
  • The FCC requires identification of transmitters at 10-minute intervals.  The W7DG repeaters identify themselves automatically.  Rick's radio will be transmitting non-simultaneously on two different bands, so needs to be ID'd separately.  I'll try to remember to ID his rig when I give my own call sign on 70cm->2m, and may pause on occasion to ID the 2m->70 link.  If a 2m user IDs his rig (KE7SKM) as part of their transmission, it'll save me the trouble.
  • After keying the mic, you'll need to wait slightly longer than usual before talking to avoid having the start of your transmission cut off for some people.  This is because, once you have transmitted a carrier long enough to "break the squelch" on the first repeater, it then has to do the same to the second repeater.

70cm repeater users
I recommend that everyone who is 70cm-capable test their link with the repeater.  You can do this at any time on your own, or you're welcome to join with the 2m users (see below).

2m users
Rick will activate his link for a few minutes after the net is finished on October 24th and 31st, so that you can test operation with the repeater.