[aprssig] Maryland, NoVa Voice Alert

[Bob Bruninga]

> I question the appropriateness of choosing the 
> National Simplex Calling Frequency for this 
> application.

Thanks for the comments.  But I view this as just an enhancement of our ability to do simplex calling for direct QSO between voice-alert mobiles.  The purpose of Voice alert is to allow a brief call to establish a QSY frequency for a voice contact.  Which is more or less what "52" is supposed to be.

> If this operation were to spread into areas 
> where I operate, I would indeed complain long 
> and loud about it to whomever would listen 
> and to those who would not.  I, for one, 
> often monitor and call on 146.52 while mobile 
> for simplex calls.

Which is all these are.  A simplex call from a mobile.  And the mobile will listen before he calls for any QSO that may be in progress, so he will wait his turn.

> If a high power, wide area coverage, 
> cross band repeater comes up on that 
> frequency announcing calls to a 
> repeater frequency in a 'pager-like' 
> manner, it will render the frequency 
> useless for simplex applications. 

Ah, I think you may be misinterpreting the system.  There is not a high power wide coverage transmitter.  Only the mobile user might originate a call on 52.  Ths cross band Regional Voice alert repeater simply listens to 52.  It calls on the APRS Voice Alert Channel.

> Unless the simplex operators engage their 
> T100 tone, the repeater will likely not 
> hear any on-going activity and walk-over 
> legitimate simplex operation. 

No, beacuse there is no output on 52.

> If the simplex operators engage their 
> T100 tones, then their transmissions will 
> be rebroadcast on UHF unnecessarily. 
> A lose-lose situation.

Actually no.  The purpose of this system is to improve the ability of mobiles and simplex operators to find each other in the darkness of our broad frequency domain instead of passing like ships in the night.  The only reason to monitor the UHF output is to learn of nearby simplex users...  If we hear other 52 users (on the UHF output) looking to make contact, then all the better...

> The 146.52 frequency has been used for 
> Simplex Calling for many years. If you 
> have not heard activity on it perhaps 
> you should listen a bit.

Yes, simplex calling is all that Voice Alert is about.  We want to facilitate the ability of mobiles to find each other even if they do not have multiple radios so that they can monitor 146.52 all the time.  The APRS user is already full-time monitoring the APRS channel for calls.  all this UHF link provides is the ability to find a mobile over a larger area.  A simplex call on 52 from a mobile (on a channel he monitors first for activity) to use the national calling channel for negotiating a common frequency or repeater to QSY to for extending a QSO.

> Please, strongly consider using a different 
> frequency other than 146.52 for this application.
> Preferably in the repeater sub-band which would 
> appear to be more suited for 'paging' applications.

The "paging" is not on 52.  The "paging" is on Voice Alert, the national APRS channel that every APRS operator monitors while mobile using his existing radio.  

And the most probable use, as you suggest, is to announce in the page, the local REPEATER that the caller is monitoring.  Normally Voice Alert is a universal capability everywhere, but this regional extension is SITE-SPECIFIC, so you are correct that the most efficient use of this capability is to suggest a central repeater instead of 52 for the call back.
This eliminates the 146.52 response in most cases.  The called mobile just QSY's to the announced reply channel.

Thanks for  the feedback.  I will be sure to emphasize the use of a central repeater as the usual response.

Bob, WB4APR