TPL vs DPL tone inquire

[camsdad]

Curious;
In a mountainous environment, are there any circumstances as to where a TPL or DPL TX/RX tone would be preferred over either other in a narrow banded VHF or UHF repeater system or simplex system.


Thanks!

Camsdad

[Jim202]

Curious;
In a mountainous environment, are there any circumstances as to where a TPL or DPL TX/RX tone would be preferred over either other in a narrow banded VHF or UHF repeater system or simplex system.


Thanks!

Camsdad

Over the many years that I have been working in the field, I have not seen any advantage of using one over the other. However, I will point out that there is one CTCSS tone that will mute any digital controlled squelch system receivers. Those that think the slick sales pitch of using a digital squelch is much better can attest to their receivers being muted by this one tone frequency.

With that said, a well maintained and adjusted tone squelch radio system will perform faster using the higher tone frequencies. The down side is that some of the radios on the market don't have a very good high pass filter on the receive audio and the higher tones can and do bleed through the voice audio. This shows up as a low pitched steady tone on the received voice audio.

Also, I have seen a number of radios coming new from the radio vendor with the tone deviation set higher than it should be. With the requirement of narrow banding in the VHF and UHF, this tone deviation level will become even more important.

Jim

[Bill_G]

+1

Both are well understood, and well supported. Definitely nothing about mountains that make one preferred over another.

[Bill_G]

Jim - from a tech's point of view, I kinda like DPL for one reason - it helps me diagnose co-channel interference while monitoring. Two users are complaining about noise. One can be heard going through with a rumble, a chugga-chugga-chugga, from his DPL beating against another carrier. Now I know it's a co-channel user, and not another system user. Very easy to hear.