Missing audio with Pro 197 and Win500

[ekmeyer]

We have two identical Pro 197 receivers, each using identical Win500 software and configuration files to record the same transmissions on two separate Windows 10 Pro 64-bit computers.

Each will create a recording of the same length for the same series of transmissions -- dispatch, response, dispatch, response, But on one or the other of them, some of the transmissions within the exchange (one of the dispatches or one of the responses) will record as silence (just a low clicking or quiet whooshing sound).

Examples attached. Files a1,wav and a2.wav are transmissions as saved by one scanner on one computer; b1.wav and b2.wav are the same transmissions as saved by the other scanner on the other computer. This situation can happen with either scanner/computer combination. One thing we have been unable to determine is whether this is a recording problem or is matched when listening live.

We'd greatly appreciate any ideas about what we might try to reduce this problem, which seems to have come up only recently, after nearly many years of monitoring the same P25 talk groups.

 

[CycleSycho]

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Hello, how close are the two scanners, and has there been any transmitters installed locally recently (like a microwave over or otherwise typical tx/rx device). If there is a part in either scanner being interfered with by the other, I would suggest a few feet separation. Thats about the only help I can offer, seeing as they both worked before. Good luck!


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[737mech]

Have you checked the computer recording settings are they the same? (line levels etc') Maybe a marginal patch cord from scanner to PC? Are you using ground loop isolators along those? Are the scanner's sharing the antenna from a splitter? Is there good port isolation on the splitter? Are the patch cords exactly the same length? If not are the scanner's antennas exactly the same? Is the squelch set exactly the same? Are both scanners loaded exactly the same number of objects? Are the tsys types exactly the same (P25 auto vs' manual)? Are there any search objects turned on? Are there any unassigned objects? Is weather "SAME" in use? Are the scanners both set to super track? Roam and Stationary the same? Order of the control channels the same? AGC set the same? Modulation for every object the same? (AM/NFM/WIDE FM) There are many things that could cause a slight delay from one to the other, I rarely see two scanners behave exactly the same side by side. As suggested maybe one is a little too close to an RF problem? Hope this info helps let us know if you find a solution.

 

[ekmeyer]

Thanks for the suggestions. The scanners are about a mile apart, the line levels are identical, and both are using brand-new audio cables, replaced after the problem was noticed. The antennas are NOT the same. One is using the rod that came with the scanner. The other, inside a building in a lower part of town, has an external antenna. I would have suspected that difference expect for the fact that both are picking up all the transmissions; it's just that sometimes, one or the other of them record silence instead of the transmission. Squelch is identical. The TSYS types are both P25 AUTO. SAME is turned off on both, as is 400 mHz "priority" settings. In fact, all programming is identical, uploaded from a single file. Neither is that close to RF except for the computers themselves and their various routers. Both have WiFi in the routers. Could transmitted SSIDs from the WiFi routers be messing with some bit in the talkgroup ID, saying it should be selected but not recorded or decoded?

 

[buddrousa]

Is this a SIMULCAST P25 SYSTEM the multiple signals may be canceling each other

 

[ekmeyer]

Not sure. Both are listening to the Aulne tower (020) of the KSICS system: Kansas Statewide Interoperable Communication System (KSICS) Trunking System, Statewide, Kansas - Scanner Frequencies

 

[Whiskey3JMC]

Both are listening to the Aulne tower (020) of the KSICS system:

Site 20 is a single site so this would rule out simulcast distortion. Though the system is P25 Phase-II and the Pro197 isn't a Phase-II scanner per-se (talkgroups are FDMA so they can be monitored using the Pro197) I'd be curious to see if more desired results would be reached with a Phase-II/TDMA capable scanner in the same location

 

[buddrousa]

The reason I thought SIMULCAST was the intermittent audio.