Users Going To Narrower Bandwidth Equipment

[Jim1348]

I am starting to notice that some radio users near me who are remaining analog, but upgrading to newer compliant equipment, going from PL to DPL. Are you folks starting to notice that also in other areas of the country?

[Bill_G]

It's a coin toss. Those with a tight budget are staying analog, and only replacing the radios needed. Those with some extra money are upgrading to Trbo for the added features.

[KG4INW]

I haven't noticed that around here. What would be the reason, you think for switching from PL to DPL? I can't think of any reason and why they initially chose one over the other, seems to be whatever the programmer felt like doing that day.

[trumpetman12]

I've noticed that going on here as well, mainly switching the tones on the input. My assumption is to make sure those with personal radios are making an effort to get them reprogrammed and switched to narrowband, otherwise the radios won't work anymore (at least on trasmit).

[Tom in D.C.]

I believe that much depends on how much effort (meaning sophistication) the agency's service shop, be it in-house or an outside contractor, puts into their work. The sharp ones know to use different PLs on the inputs and outputs of the repeaters to keep outsiders from kerchunking or otherwise interfering with the systems' operations. I have noted a slight swing to greater use of DPL as I scan the RR database, but that might be just me. Using DPL rather than CTCSS (PL) could be a result of a poor coordination effort when the licenses were obtained, something I used to experience when I was buying coordinated licenses some years ago.

[GlennD]

In our case we switched to DPL to insure the non-compliant radios like the Sabers stuck in the locker as a spare are not usable. There would be lots of radios that are left wideband that would be just in case radios.

[Bill_G]

I misread the OP. That makes no sense. Our customers rarely care whether their system is PL or DPL. We are definitely not seeing customers requesting NB and a PL/DPL change. The closest we got to that was a national school bus company with a confusing mix of radio models in some yards. It was fubar mess.

We are up to our eyeballs in system upgrades to Trbo however. 60 hour weeks is the norm right now trying to keep up.

[thebigphish]

"digitull is bettur"

DPL > PL

Someone sold someone on that logic!

[k2hz]

I think there is a perception that DPL has some advantages over PL such as more available codes and possibly better
performance at the lower deviation levels.

Switching from PL to DPL in the past was not always an easy option since some older radios could not do DPL. With the change to all NB compliant radios, DPL was a standard feature. If it was just a case of blocking non-compliant radios all that needed to be done was to change the existing PL.

[KB2ZTX]

In reading this thread I must admit some of this makes sense. I didn't think about changing a PL/DPL on our infastructure but have been seriuosly wondering how to get all the radios that are users of the system reprogrammed to the new requirements. Maybe switching the PL/DPL is a easy way to get this done as users will not be able to access the repeaters without the reprogram. In the volunteer SAR world i livei n many member buy there own radios and it took us 20 years just to get everyone on a common PL tone...switching to 12.5 Khz spacing is going to be even harder.

[Bill_G]

In reading this thread I must admit some of this makes sense. I didn't think about changing a PL/DPL on our infastructure but have been seriuosly wondering how to get all the radios that are users of the system reprogrammed to the new requirements. Maybe switching the PL/DPL is a easy way to get this done as users will not be able to access the repeaters without the reprogram. In the volunteer SAR world i livei n many member buy there own radios and it took us 20 years just to get everyone on a common PL tone...switching to 12.5 Khz spacing is going to be even harder.

Ok. Now that makes sense. If you are a system owner, and you want to ensure compliance, or you want an accurate count of the number of users, changing the access PL would force them to get their radios programmed. However, if you are not in total control of radio maintenance, you will not see every radio in a conventional system. Other shops, or their "friends", will see some portion of the radios.

[tdats]

We took the narrow-banding reprogramming opportunity to change the input PL on our repeaters to help with interference issues we have been fighting. We scanned our input for a while counting PL hits until we found a couple that we where not receiving. We stuck with an analog PL though, but I suppose we could of went to a DPL. I wounder if other repeater operators are doing something similar. Changing the PL to make sure every radio gets re-programmed though is not a bad idea. I have heard a few though that sound like they are still wideband around here, but have our new PL, so it is not foolproof.

[KB2ZTX]

Correct Bill, but at least I will hear from each person that needs this completed when they are looking for the PL/DPL code that I change it to. With the amount of work any radio tech has going on right now in regards to the deadline I am fine with people going other places to get reprogrammed. Although this wouldnt solve 100% of the issues Im sure it would bring 95% of the radios into complience. The larger issue is getting folks to spend funds on a new radio when we tell them the old one cannot be used.

[resqroz]

I just changed one of our systems to narrowband. I chose a different PL to make sure that I would catch all of the radios that needed to be changed when they didn't work on the new system. I chose DPL because we had a few places in our building where computer noise would false the pl opening.

[Jim202]

One big negative that I know of going to a digital code is that you can shut it all off by using a PL of 136.5. It turns off all the digital coded receivers that might be listening to a signal.

Use to do that with a taxi outfit on the same business frequency as I had a number of years ago. Every time I keyed up my base, it would kill anything they might be listening to unless they had a stronger signal than mine. They would never shut up and just kept jabbering about nothing just to keep the channel tied up.

Jim

[motorola_otaku]

In the instances I've noticed, it was done to mitigate long-standing issues with skip interference. This has been primarily among VHF-highband licenses.