[time-nuts] Re: Synergy replacement receiver boards for Z3801A

[Bob Camp]

Hi

All of these old GPSDO’s date far enough back that their GPS modules are going to get into “roll over” issues. Their internal date computation will be off as a result. In some cases this is just a bother. In other use cases it can be a big deal.

Technology has come a very long way since the 1990’s when some of the original modules were designed. Even on a LEA-6 generation part, there is a lot more “horsepower under the hood”. That will help with faster acquisition. It will improve things like sorting out false signals. It lets them deal with more satellites at one time (which will help you lock on to those sats more quickly). 

Some (but not all) of the early GPSDO’s used correction messages to improve the resolution of the PPS. The newer modules do a better job of this than the early ones did. If the GPSDO uses the raw pulse by itself, the range of that pulse wanders over is smaller on newer modules. 

As the years go by radio front ends take a lot of abuse. Something that is on 24 hours a day 365 days a year will see a lot of lightning and other nasty stuff. Eventually that degrades the front end. 

Is any of that a reason you *must* upgrade right now? No. If it was me and the GPSDO was being used for something like a local standard, I *would* very much do the upgrade. This module is very much the one to use in that case.

Bob


> On Jan 30, 2024, at 10:43 AM, lmcdavid via time-nuts <time-nuts at lists.febo.com> wrote:
> 
> Please, someone point to a description of features and advantages of this replacement receiver for the Z-3801a. And, how it is sourced.I have three Z-3801A and have had one receiver fail.LarrySent via the Samsung Galaxy S10
> -------- Original message --------From: Lon Cottingham via time-nuts <time-nuts at lists.febo.com> Date: 1/30/24  7:10 AM  (GMT-08:00) To: time-nuts at lists.febo.com Cc: Lon Cottingham <k5jv at kingwoodcable.com> Subject: [time-nuts] Synergy replacement receiver boards for Z3801A Greetings to all,       I have just installed the new boards in two Z3801A's.  Both came up immediately with GPS lock in four minutes on one and 35 minutes on the other.  Not bad considering the last time were on was from some location in China.         All of my Z3801A's have the G4FRE/WW2R clock from K8UC's board installed.  With the original receiver board the clock would display a series of dots and a number increasing from 1 to 3 with a clock/date turn on at 4.  This might take from a few minutes to a few hours.  With the new board, the dots display and blink 8 to 10 times and the clock display turns on.  This takes from a few seconds to two minutes.  As I said above, GPS locks quickly.  The first unit came up ls almost instantly, then reset and displayed an error.  It did this three times before stable operation was achieved.  The second unit came on immediately with no reset or error.  Both units have been stable, with GPS lock for over an hour.  I will let them run for a week and report again.73 de Lon, K5JV281-795-1335_______________________________________________time-nuts mailing list -- time-nuts at lists.febo.comTo unsubscribe send an email to time-nuts-leave at lists.febo.com
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