440Re: [RTrak] RTrak Tuning?
- Oct 26, 2012
> (1) My 2m voice rig occasionally picks up the beacons from the RTrak when I'm> tuned to 145.390 (local repeater) even though the RTrak is broadcasting on> 144.390, and...Are you set up for dual frequency operation? That could cause what you are describing. There is also the chance that your mobile might not have very good adjacent channel rejection and you're hearing a harmonic.
> (2) Compared to my earlier setup (an OT w/ a Yaesu VX-170) my packets aren't> being consistently picked up by the local APRS network. I'd say maybe 1 out of 4> transmissions is successful.That does sound like the deviation is not correct. When you say "picked up by local APRS network" how are you verifying that? Direct decode local with an actual radio? Looking online to see if it shows up? If it's the latter, keep in mind the transmitter is only 350mW, so unless you are in the air or fairly close to a digipeater, I don't expect the RTrak-HAB to show up online. It's all about being heard by an iGate, to get the packet to the internet.
> Based on the above, I'm wondering if I have a transmitter deviation problem.> What's the best way to "tune" the RTrak?The BEST way is with a calibrated RF service monitor that has a deviation meter. In general the packet audio should be 3.5-4 kHz. I tend to find that it needs to be on the higher 4 kHz end. We "marry" each tracker to an MX145H transmitter and then do final alignment. That way, you're getting an aligned tracker with the actual transmitter that it ships with.If you don't have access to an RF service monitor, one method is to listen to other packets on the network and then try to adjust the RTrak-HAB to transmit at roughly the same audible level. This can be hard for some people to do, but it's not too difficult to get close. 1200 baud packet is somewhat forgiving in this regard, but it can't be too out of whack or else nothing will decode it.
Jason Rausch - KE4NYVRPC Electronics, LLCwww.rpc-electronics.com
--- On Thu, 10/25/12, sdrumm_98 <swdrumm@...> wrote:
From: sdrumm_98 <swdrumm@...>
Subject: [RTrak] RTrak Tuning?
Date: Thursday, October 25, 2012, 11:02 PM
I've noticed two problems with my latest RTrak installation:
(1) My 2m voice rig occasionally picks up the beacons from the RTrak when I'm tuned to 145.390 (local repeater) even though the RTrak is broadcasting on 144.390, and...
(2) Compared to my earlier setup (an OT w/ a Yaesu VX-170) my packets aren't being consistently picked up by the local APRS network. I'd say maybe 1 out of 4 transmissions is successful.
Based on the above, I'm wondering if I have a transmitter deviation problem. What's the best way to "tune" the RTrak?
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