SDRTrunk - Fine Tuning

[BM82557]

Late to the party but from your one screen grab your PPM adjustment is off --




Like someone else posted the closer to zero is what you want, mine is running at --

 

[dave3825]

Generally that's not the best way to split an antenna but on strong signals it really does not have much of a negative impact.


Can you stop the channel, and go changeC4FM to LSM and change 400 to 1200? Then restart and see if you get a lock?

 

[K0MSM]

It's seemingly trying to latch onto something... ;-)

 

[K0MSM]

Late to the party but from your one screen grab your PPM adjustment is off --

View attachment 181615


Like someone else posted the closer to zero is what you want, mine is running at --

View attachment 181616

Mine is all over the place, currently. It'll be as low as -2300 or so, then as high as 2000.

Sean

 

[K0MSM]

Generally that's not the best way to split an antenna but on strong signals it really does not have much of a negative impact.


Can you stop the channel, and go changeC4FM to LSM and change 400 to 1200? Then restart and see if you get a lock?

View attachment 181617

Yeah, the right / best way to split the antenna is another discussion at another time. I need to figure that out too.

I disconnected the 200, and the coax is going directly to the SDR now. No T. Making the changes you suggested had no effect.

Sean

 

[K0MSM]

Well -

I switched over to the next county over, and lookie here:



I have NO idea why I can pick up that county, but can't pick up my own. Absolutely odd to me. Although... I was using a cheap little cable TV splitter for a while to split the signals to different spots in my shack. I took that out of the mix when I discovered that my own county's P25 system wouldn't go through that (even though every OTHER county's system would). Now, here we are, and the dongle is happy with Boone County, but not my own. Maybe there is some sort of a gremlin somewhere on my county's frequency?

I'm completely lost for answers.

Sean

 

[dlwtrunked]

When I started up the software, the waterfall was showing the audio frequency way off from where I would have expected it to be. I could remove the "correction" I suppose, and see what happens. But at least, at the moment anyway, the audio is showing up more or less where it's listed in the RRDB. SDRTrunk just isn't locking on to a control signal. (And I don't see that in the waterfall either.)

Sean

I can understand this as possible if the calibration was "way off". But do not expect it now to be "dead-on".

 

[dave3825]

Maybe it's a bad dongle. Don't know. I've ordered a new one (seeing as this one is about 10 years old, and I'm sure things have changed since then). Interesting to note, that while RRDB 771.76875 as one of my county's frequencies, the SDS-200 shows that it's actually picking up on 771.46875. (And it's using the other frequency of 772.56875.)

I have NO idea why I can pick up that county, but can't pick up my own.

I am thinking since the db only lists 2 freqs for Greene site, 771.76875 and 772.56875, and the sds is saying its receiving on 771.46875, I would add that freq (771.46875) to the 2 freqs in SDRTrunk. Possible all the sites freqs were not submitted to the database..

If you happen to have @ProScan , leave the system running in that and then review the logged history and see if there are any other freqs other than the 2 listed in the database.

 

[K0MSM]

This was a comedy of two errors, it seems....

1) I switched from my discone to my dual-band (2/440) antenna.... and bingo, we're up and running. Cooking with gas. High flame.

2) We do need to update the RRDB with the new frequency, as shown here:


There needs to be 3 frequencies shown now for Greene County. I'll submit that change request.

Oh, and a 3rd problem that didn't really show itself tonight, but DID show itself in the past, is the splitter. I need to get a new one. Many thanks to @mtindor for his help on the phone a short time ago. It made a huge difference having a second set of eyes/ears to bounce things around with, and to find out what all the "cool kids" are using to split signals these days.

I at least have a V5 SDR coming next week. Should be an upgrade from the 10 year old E4000, hmm?

Thank you ALL for your help on this.

Sean

 

[DaveNF2G]

Have you tried any of this with other software, such as DSDPlus?

I would trust what my scanner is telling me over a crowdsourced database.

 

[K0MSM]

Have you tried any of this with other software, such as DSDPlus?

I would trust what my scanner is telling me over a crowdsourced database.

Yes, this is confirmed. Scanner shows the new frequency, and SDRTrunk matches what we're seeing. Plus, the frequency information comes straight from ISICS, who runs the system, so that's pretty solid for me.

Sean

 

[Enforcer52]

I switched from my discone to my dual-band (2/440) antenna.... and bingo, we're up and running.

Exactly why I never recommend a discone antenna on 700-800mhz!

 

[dave3825]

I am thinking since the db only lists 2 freqs for Greene site, 771.76875 and 772.56875, and the sds is saying its receiving on 771.46875, I would add that freq (771.46875) to the 2 freqs in SDRTrunk. Possible all the sites freqs were not submitted to the database.

Keep an eye open as you may find addition freqs not listed in the database on any of those sites.

find out what all the "cool kids" are using to split signals these days.

I use one of these to split to scanners and dongles. For my needs the 8 port does a perfect job.

https://www.electroline.com/fact_sheets/eda/950-0014_New_EDA-2000_fact_sheet.pdf

 

[DaveNF2G]

K0MSM said:

find out what all the "cool kids" are using to split signals these days.

 

[K0MSM]

Exactly why I never recommend a discone antenna on 700-800mhz!

Cursory glance for scanner antennae seems to always pull up a discone. (At least on Amazon, which is why this was just a cursory glance.) While my *primary* scanning is on 7/800, I do also monitor RR and air, so I need to have VHF ability. What would you recommend?

Sean

 

[dave3825]

Antenna tuned for the band of operation work the best. I no longer use my discone as I was not happy with 7/8/900 performance. For local stuff where those towers are close, the discone will work perfectly fine. For distant towers it just sucks.

For rail and air, a vhf antenna with good gain will work wonders. One can have an antenna for vhf and and antenna for uhf and use a duplexer. One can even use 3 different antennas (tuned for freqs of interest) and use a triplexer.

Panorama TPX-VH-UHF-BA-TNC Triplexer for VHF, UHF, and 7/800 MHz Signals

TPX-VH-UHF-BA-TNC Panorama Triplexer to Use One Antenna with Three RadiosThe TPX-VH-UHF-BA-TNC Panorama Triplexer can either combine VHF, UHF, or 700/800 MHz signals from three antennas to a single multiband radio or split the signal from a tri-band radio to three radios. Switching or

westwardsales.com

 

[Enforcer52]

The OmniX antenna is what I and a lot of others on RR use, works very well on VHF, UHF, and 700-800 range.

OmniX Scanner Base Antenna

Specs Gain: 3 VHF 4 UHF dBi Pattern: Omni-directional Wavelength: 1/2 Elements: 3 Tuned: 118-137, 148-175 & 225-900 MHz Band: UHF & VHF Connector: N Female Cable: RG8X Cable Length: 16 Inches Height: 45" Width: 30" Weight: 2 lb Features Multi Band-Wide Coverage: The uniquely...

dpdproductions.com

 

[K0MSM]

Back on the topic of this thread... I moved the discone up about 4-5 feet higher, and I believe it has made a world of difference. I think it was getting shielded by my metal roof a little bit, which coincidentally, was between the discone and the ISICS site I was trying to monitor. See the screen shot below:

While still not as strong as I'd expect from a site that's only about 10-15 miles away, it's now MUCH stronger than it was. It's holding lock on the control much better now, and even my SDS-200 is showing 2 bars on it's strength meter (which it never showed before).

Metal roof shielding. Probably should have figured that one out on my own.

I've ordered the powered splitter that was recommended plus a new dongle. I may get super adventurous and build the Raspberry PI model for monitoring so I can run more than one dongle easily and not worry about tying up my shack PC with that (or having it shut down unexpectedly when Windows does it's mandatory updates). I could see feeding more than just Greene County into Calls. I'll look and see if the other counties around me need some loving too.

For antenna options, thank you for the suggestions. I'll take a look at what's out there and make an upgrade in a few weeks perhaps.

One step at a time.

Again, thank you ALL for your help with this. I'd like to think I'm not stupid when it comes to this stuff, just not as experienced as all of you. And sometimes, it just takes another set of eyes/ears to work things through and listen to you mind grind a little bit, right @mtindor ?

Sean

 

[dave3825]

lol. My daily pc has windows updates turned off and runs DSDPlus, Unitrunker, sdrtrunk and trunking recorder. Sdrtrunk is chugging away with three different systems and it is doing 2.

Glad it’s working much better for you

 

[K0MSM]

I don't know HOW many times I've tried turning that stupid WU service off... and it still pops up from time to time. It's the main reason I jumped into the Pi world and moved Home Assistant from a VM over to a Pi. I was tired of my HA operations grinding to a halt unexpectedly!

I enjoyed the pictures of your setup, and I appreciate all the help.

Sean