[time-nuts] Re: GPSDO replacement recommendation

[David G. McGaw]

Indeed.  I state the limits.  I have a number of packaged Samsungs from 
amoj1010 (apparently no longer available) that the internal regulator 
was set at around 6V.  The module was working but had the Power Fail 
light on.  Sweeping their limits, the Power Fail light will be set below 
5.0V and above 5.5V.  I changed the resistors on the supplying regulator 
to give 5.25V.

Ours use a RPi3 host running Lady Heather for monitoring.  See 
<https://hamsci.org/publications/traveling-ionospheric-disturbances-observed-using-doppler-measurements-clear%E2%80%90channel-am>, 
PDF of the presentation at the bottom.

73,

David N1HAC

On 4/15/24 12:04 PM, Wilko Bulte wrote:
> [You don't often get email from wkb at xs4all.nl. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
>
> hello David,
>
> Both Samsung UCCM I own are not satisfied with a 5 V supply, the need 5.5 V. So I advise a bit more than 5 V. There is a LDO on the Samsung UCCM so it will do its own onboard power cleanup.
>
> One of them is equipped with a OrangePi (RaspberryPi lookalike) which runs Linux with LadyHeather. This makes for a standalone unit that, once connected to the LAN, can be monitored via the network/LH.
>
> For a house standard this works quite nicely, not needing an always-on PC, but rather a low power *Pi taking care of the monitoring chores.
>
> Wilko PA1WBU
>
>> On 15 Apr 2024, at 17:30, David G. McGaw via time-nuts <time-nuts at lists.febo.com> wrote:
>>
>> The only caution for the Samsung version is it has a bit different serial protocol, but Lady Heather version 6.14 knows how to talk to it.  There is also a patch that helps - grounding pin 39 of the 50-pin connector to sync to the internal GPS PPS (this is true of all versions).  The Samsung is also very critical for supply voltage, 5V min, 5.5V max, to keep the power fail light off.  I have several of all versions.
>>
>> David N1HAC
>>
>>> On 4/15/24 8:43 AM, Wilko Bulte via time-nuts wrote:
>>>     another option would be a Furuno GF-8705
>>>
>>>     ogp.png
>>>     [1]GF-8705 from FURUNO ELECTRIC (Multi-GNSS Disciplined Oscillator)
>>>     [2]qzss.go.jp
>>>
>>>     I obtained one for €40. It has a sensitive GPS rx, is fast to acquire
>>>     lock and is a compact, even smaller than the UCCM. For those that care:
>>>     it sports a programmable clock output too.
>>>
>>>     Downside: LH does not know about it. There is free Furuno software to
>>>     program and monitor it.
>>>
>>>     hth,
>>>
>>>     Wilko
>>>
>>>       On 15 Apr 2024, at 14:12, Wilko Bulte <wkb at xs4all.nl> wrote:
>>>
>>>     hi Atilla,
>>>     Assuming you can find one: the Samsung UCCM is form/fit compatible but
>>>     sports a much more sensitive GPS module. Fast satellite lock with
>>>     signal levels that made Trimble and Symm. UCCM modules very slow to
>>>     acquire lock.
>>>     I happen to own 2 of these Samsungs. Previously also had both a Trimble
>>>     and a Symm UCCM. The Samsungs were to stay.
>>>     hth,
>>>     Wilko
>>>
>>>       On 14 Apr 2024, at 15:17, Attila Kinali via time-nuts
>>>       <time-nuts at lists.febo.com> wrote:
>>>
>>>       Moin,
>>>
>>>       My house GPSDO (a Trimble UCCM) died recently and I am now looking
>>>       for a
>>>
>>>       replacement. As I have been a bit out of touch with the current
>>>       state
>>>
>>>       of affairs regarding GPSDOs, I'd like to ask what the current
>>>       recommendation
>>>
>>>       for getting a GPSDO is, these days.
>>>
>>>       Thanks in advance
>>>
>>>                 Attila Kinali
>>>
>>>       --
>>>
>>>       Science is made up of so many things that appear obvious
>>>
>>>       after they are explained. -- Pardot Kynes
>>>
>>>       _______________________________________________
>>>
>>>       time-nuts mailing list -- time-nuts at lists.febo.com
>>>
>>>       To unsubscribe send an email to time-nuts-leave at lists.febo.com
>>>
>>>
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at lists.febo.com
>>> To unsubscribe send an email to time-nuts-leave at lists.febo.com
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at lists.febo.com
>> To unsubscribe send an email to time-nuts-leave at lists.febo.com