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Mercury "Pen" pager...

Posted: Mon Mar 01, 2021 3:47 pm
by G8OGJ
Folks,

I recently found my old Mercury Paging "Pen" pager which is set on 143MHz or thereabouts. I guess that it dates from the early 1990s and I presume that it is a POCSAG device - am I likely to be correct in that assumption? As I recall battery life with zinc-air cells was just over a week.

Does anyone have any experience with these devices? Should I just be able to swap the crystal and get it to work on 2m? If so, I would be more than happy to build a dedicated POCSAG unit. If we're to get long term access to the 146-147MHz sub-band that might be an ideal space for it. I have a small PBX at home that I could also use for dial-ins.

Thoughts?

Ian

Re: Mercury "Pen" pager...

Posted: Fri Mar 05, 2021 8:16 am
by MW0MWZ
G8OGJ wrote:
Mon Mar 01, 2021 3:47 pm
Folks,

I recently found my old Mercury Paging "Pen" pager which is set on 143MHz or thereabouts. I guess that it dates from the early 1990s and I presume that it is a POCSAG device - am I likely to be correct in that assumption? As I recall battery life with zinc-air cells was just over a week.

Does anyone have any experience with these devices? Should I just be able to swap the crystal and get it to work on 2m? If so, I would be more than happy to build a dedicated POCSAG unit. If we're to get long term access to the 146-147MHz sub-band that might be an ideal space for it. I have a small PBX at home that I could also use for dial-ins.

Thoughts?

Ian
In the ham world, there is a somewhat standard (as in used by a lot of people, but not written in the band plan) frequency of 439.9875
While there is no special reason not to use 2m, it would equally be a good idea to use a single spot frequency, like is done on 70cm.

Getting back to your first question, yes it probably is pocsag. I also have a 153MHz (was Vodafone) pager, that I kinda wish I could get going too, older devices are probably crystal, newer ones were programmable so that they could be multi-vendor.

I dont expect this helps a whole lot, but I'm interested in your progress all the same :)

Re: Mercury "Pen" pager...

Posted: Wed Mar 10, 2021 4:24 pm
by G8OGJ
Thanks for the reply. I am confident that it is a single xtal device. Quite what cut the crystal is remains to be determined. I agree that a spot frequency would be ideally agreed. Pager networks are often criticised as noise-generators, not unreasonably in my view, so perhaps something out of the way such as in the NoV segment might be more appropriate.

First job is to identify the crystal, what cut it is, and find someone to make a new one for <any> 2m frequency. Are QSL and so forth even still trading?

I'm presuming that C&W/Mercury bought these in bulk and that they were a generic design and therefore that the front-end tuning is minimal such that in this case I will only need to replace the crystal as the percentage bandwidth change is rather small...???

Ian