Strange Type I / IIi System Behaviour

[kh6jjn]

I realize this is not directly ASTRO related, but I've observed some strange behaviour and would like someone who is familiar with this to comment on my observations:

Our 800Mhz (analog) trunking system was recently upgraded from privacy-plus (type I) to Type IIi. In the course of setting up some radios for IIi, we inadvertantly programmed a radio for straight type II (*not* IIi). The radio didn't seem work; it was able to transmit, but it couldn't hear any of the type I radios. . . .

Except *ONE*

One of our *Type I* portables was able to talk to it (and vice-versa). It's unit ID was Zero. Further investigation showed that if the unit ID was less than 7, *any* type I radio could talk to the type two radios, assuming of course that the talkgroups/subfleets coincide.

Has anyone else observed this? I don't recall anyone mentioning this phenomenon before. What are the overall implications/consequences of running Type I radios on a IIi system with ID's set this way?

Any comments would be *most* appreciated . . . .

[wavetar]

That is a strange one. Unfortunately, the only Type IIi system I could've tested that scenario on was dismantled last year. So I don't know if it's "normal" or not. I do recall a Motorola FTR once telling me to avoid using IDs less than 16 in a Type II system. Claimed unpredictable things could happen because they could be used internal to the controller for it's own communications processes...something like that anyway. I've made it a habit to start my IDs at 100 ever since.

Todd