Patching Questions

[cwcrowley]

From what I can tell this question has not been asked and it has was a long while ago.
Back story: I'm a HEMS dispatcher (Air medical/Helicopter), we are looking to upgrade our radios from EF Johonson (VHF Trunked/Analog) and Moto APX Tri-brand radios. We are also looking to upgrade our current Telex Radio Counsels. Prior to parks of our service areas switching over to Digital VHF or 800 Trunked systems, we had the ability to patch. Now that many of our service areas have made that switch, we can no longer patch selected frequencies/talk groups to others. (Examples: Our Air Band Frq to USCG 16, Analog VHF LZ Channel to 800 Digital Trunked LZ Channel) For those that are going to ask why, this is to help streamline in the event we request Mutual Aid from a neighboring service that does not have access to systems we have access to.

As Stated above, in the past we have been able to patch with no issues, however as of late, we no longer have the ability to patch. I'm not sure if this is due to outdated Telex Softwear or if there is something more to it. While attempting to assist National Guard Helo's with a hospital EMS report and security check, we were told by one system tech (Tech 1), that it's not possible do that type of patch. Analog to digital. (We were able to get them on a digital VHF Talk group and patch it with the hospital Digital 800 Talk group.) We reached out to other counties and asked for guidance from their teams. A neighboring area built a patch for the VHF Analog LZ frequency to the Digital 800 LZ frequency. Great, or so we thought, until we found that that has had a high turn around rate for their emergency dispatcher and we (at times need to walk them through it.) A third neighboring area has their system patch setup 24/7 (or at least it seems that's way. The first two locations use the same 800 Digital TG for LZ's. the third area is on their own digital system.

My question, is it possible to create patches for analog to digital? Are there any additional steps we need to include when we update? (We are getting ride of our early 2000's Telex)

Thank you in advance

 

[TampaTyron]

Yes, you can patch almost anything to almosy anything. This assumes the equipment is setup correctly AND the audio levels are not crap.

However, some agencies disallow patching on their system unless THEY initiate the patch (common here in AZ with the regional radio systems).

In FL, we would patch anything to anything all the time, no worries.

There are technical limitations and political limitations. My limitation is not always knowing the difference.

TT

 

[tweiss3]

Honestly these are questions for the contractor that is replacing equipment and the system administrators for each system you need to patch.

 

[vickings]

Yes, you can patch almost anything to almosy anything. This assumes the equipment is setup correctly AND the audio levels are not crap.

However, some agencies disallow patching on their system unless THEY initiate the patch (common here in AZ with the regional radio systems).

In FL, we would patch anything to anything all the time, no worries.

There are technical limitations and political limitations. My limitation is not always knowing the difference.

TT

informative thanks.

 

[speedway_navigator]

The patch our county has with Marion county to the east of of has sounded bad the last 2 or 3 times it's been use. Audio is distorted and usually I only hear 2 or 3 words and it drops out. I but it never gets reported since it's used about once a year for under an hour.

JPS and others have been doing this for years, like TT said there is no magic, just logistics. A basic patch is receive audio from one radio going to the mic input on the other and vice versa, then the control signal to key the radio when it hears RX audio. I'm not a radio over IP expert, maybe there is a way to do this within the P25 ISSI system.

Patching became more challenging with trunked systems due to the delay in getting a permit to talk tone after hitting the PTT button but that's been worked out for a long time. A friend of mine on a California SAR team said he finds the state's CALCORD VHF simplex a quick and easy way to talk to copters on approach rather than jumping through zones and channels based on the agency or company responding.