SDRTrunk MPT-1327

[morfis]

In Events it showed:
002-0023 connected to 002-6023. Channel 280 and that was the same for both conversations, the only difference was the Frequency field showed 5.10675 the first time and 3.99817 the second. Thoughts?

First, you don't have your base frequency set in Hz

Second, as the calculation of the channel fequency is the same I don't understand how it's possible for the software to arrive at two different answers from the same input values.

I've never heard of TrunkView, is this scanner discriminator-tap driven application and will it run on Windows 10 do you know?

Generally, slow speed data like MPT1327 don't need a 'discriminator' output (but will work with one if that's what you have).
Above screenshot was from a Windows 10 machine and using headphone audio from a Pro2042

 

[grosminet]

Trunkview is working fine for years .

 

[Bowlieweekender]

First, you don't have your base frequency set in Hz

Second, as the calculation of the channel fequency is the same I don't understand how it's possible for the software to arrive at two different answers from the same input values.



Generally, slow speed data like MPT1327 don't need a 'discriminator' output (but will work with one if that's what you have).
Above screenshot was from a Windows 10 machine and using headphone audio from a Pro2042

Thanks for the assistance

I'm still not getting how to arrive at this base frequency, what should the magical number be?

Two Windows 10 machines refused to run TrunkView v2.21 this end, and both gave the same odd messages (Cannot change Visible in OnShow or OnHide). I'll start trying compatibility mode options.

 

[morfis]

Thanks for the assistance

I'm still not getting how to arrive at this base frequency, what should the magical number be?

Two Windows 10 machines refused to run TrunkView v2.21 this end, and both gave the same odd messages (Cannot change Visible in OnShow or OnHide). I'll start trying compatibility mode options.

Never had a problem running Trunkview on any recent flavour of windows and never needed to look at 'compatability mode options' (never had to use them for ANY windows radio software that I've used).

No magical umber - you'll have to do some work.

In the US you generally have access to detailed frequency information for organisations but even with that you need to do some work to build a channel plan for sdrtrunk and MPT1327. Re-read Denny's new FAQ (option 1 and 2) and perhaps refer back to my 'example' post.

Realisticly you need to get at least two frequency channel number pairs identifiedand then do a bit of math(s).

 

[morfis]

From the image:
sdrtrunk has an mpt1327 decoder set on 181.9875 (green arrow). It shows as a control channel because the decoder identifies the data type
Monitoring the MESSAGES from the decoder but to make life easy have all messages EXCEPT Goto filtered out.
A data channel can be seen to have come active (red arrow) and a GOTO message decoded. From the screen I can see the frequency (181.6875 using the mouse to get an accurate reading) and from the message I can see the channel number (the bit highlighted red) - so there is one pair.

Next set an mpt1327 decoder to the newly seen frequency and again monitor the messages (no need to filter this time as you won't have them whisltling past). You are looking for the CLEARDOWN as shown in my image earlier in the thread.
That message confirms the active channel number AND gives the channel number of the control channel and thus a second pair.
Follow the simple math(s).

Obviously your system will be different numbers but the methodology is the same.

 

[Bowlieweekender]

From the image:
sdrtrunk has an mpt1327 decoder set on 181.9875 (green arrow). It shows as a control channel because the decoder identifies the data type
Monitoring the MESSAGES from the decoder but to make life easy have all messages EXCEPT Goto filtered out.
A data channel can be seen to have come active (red arrow) and a GOTO message decoded. From the screen I can see the frequency (181.6875 using the mouse to get an accurate reading) and from the message I can see the channel number (the bit highlighted red) - so there is one pair.

Next set an mpt1327 decoder to the newly seen frequency and again monitor the messages (no need to filter this time as you won't have them whisltling past). You are looking for the CLEARDOWN as shown in my image earlier in the thread.
That message confirms the active channel number AND gives the channel number of the control channel and thus a second pair.
Follow the simple math(s).

Obviously your system will be different numbers but the methodology is the same.

Super helpful thank you. Clearing out the clutter and just leaving GTC ticked will make it much easier this end. And now I wait for strong winds or an idiot to drive into a power pole. How do they get away with not having to list all their channels with the FCC I wonder. Their competitor Central Electric is all detailed channel by channel.