Differences between Mk I, II, III, IV?

[sjefferson]

Does someone have a list of differences between the different models or how to ID them?

[egomon]

Perhaps this will be a little help to you


[url]http://www.soluhr.com/sync.htm
[/url]

[egomon]

It seems that my previous text is gone missing:

Perhaps this will help you
[url]
http://www.soluhr.com/sync.htm
[/url]

[charger105]

A brief description of each model:

Mk1 - red bottom, factory speed adjustment via trimmer, time, date/month and running seconds only. 6 reed switches. Dot display.

Mk2: - same as above, but can be S/W speed adjusted(not displayed). Has a leap year indicator (1-4). Most I've seen have 4 reed switches (one at the rear), some have 5 or 6(?). Dot display or bar display.

Mk3 - generally black bottom (I have seen a couple of red bottom versions). Sunwatch version available (either flat-top or plastic bar down centre). 4 reed switches only (none at rear). S/W speed adjustable to a better accuracy than Mk2, and speed is displayed. DOW feature. Bar display.

MkIV - Black bottom, some have a SS plate attached. Same features as Mk3, but also has stopwatch, 2 time zones, visual alarm. No sunwatch version produced I don't think. Bar display.

I think that just about covers it.
Rgds.

[dot matrix]

A brief description of each model:
Mk3 - generally black bottom (I have seen a couple of red bottom versions). Sunwatch version available (either flat-top or plastic bar down centre). 4 reed switches only (none at rear). S/W speed adjustable to a better accuracy than Mk2, and speed is displayed. DOW feature. Bar display.

MkIV - Black bottom, some have a SS plate attached. Same features as Mk3, but also has stopwatch, 2 time zones, visual alarm. No sunwatch version produced I don't think. Bar display.

The MkIV had a reduced number of automatic display brightnesses than the III, and the IV also had an automatic Daylight Savings Time feature that could be turned on or off. The built-in date range for DST was limited to the U.S. date range but eventually became obselete when the U.S. goverment changed the DST date range.

[azimuth_pl]

Here is a set of pictures taken last year for my website that I still haven't had the time to post in the Synchronar review.
http://www.crazywatches.pl/synchronar-2100-riehl-solar-led-1974
Hope this helps for many enthusiasts to differentiate the modules, mind that there were a few transitional/mixed modules eg Mark2 with Mark1 display, etc.

Revised after below comments from Andy, thanks! Any new input is welcome.
MkI - early and late version - top (mind the first MkI with a 1974 production chip, later than 1972 production Pulsar)

MkI - early and late version - bottom

MkIII - early and late version - top

MkIII - early and late version - bottom


MkI - early version - top and bottom

MkI - late version - top and bottom

MkIII - early version - top and bottom

MkIII - late version - top and bottom

[charger105]

The images above show Mk1 and MkIII modules only.
MkII modules do not have a trimmer, and have one connection from the rear reed switches "cut" on the PCB.
MkIV modules have a square chip (i.e. not rectangular).

Rgds.

[azimuth_pl]

I'm not an expert on the Synchronar but having a load of parts from Barry it's hard to believe there would not be a single Mark2 among them.
how would then a Mark2 look like exactly....going towards the Mark1 or Mark 3?
how would you also describe the modules shown if their build is totally different and showing progress in development?
the last one might be a Mark3,5 if such a terminology is allowed, it's an upgraded version of Mark3;)
there are transitional modules hence confusion is always around.

[charger105]

Hi Piotr.
There are many PCB variants for at least the MkIs and MkIIIs. It seems Mr. Riehl was constantly refining the PCB layouts for these models.

The MkIIs do seem a lot less common than the MkIs. It looks very similar to a Mk1, but as mentioned, has no trimmer, has one of the rear reed connections to the IC cut and bridged on the PCB and indeed only has 1 rear reed. A few of the discreet components were also integrated into the IC (the resistors between the command reeds and the IC for example). I'll load up a picture tomorrow.
Jeff Thomas and I had a discussion on this topic a while back, but unfortunately he deleted all of his posts :
viewtopic.php?f=81&t=3757&p=23556&hilit=integrated#p23556

The only MkIVs I've seen have either an encapsulated IC or a square IC. The ones shown look like classic MKIIIs to me.
Rgds,
Andrew.

[azimuth_pl]

Many thanks Andrew, perhaps one day we will have a picture database of all these different modules in one place for reference ;)

[charger105]

Here's a picture of one side of a MkII module:


I've circled differences in the duplicated image on the right-hand side. The orange circle shows where one leg of the IC has been cut and is left unconnected. On a MkI this is the leg which connects to one of the rear reeds, which is missing on the MkII(see next image on other side of board).
The green enamelled wire (circled in green) bridges the IC leg which normally connects to the left-away reeds on a MkI for hours adjustment, which is missing on a MKII(circled in pink), to the single remaining rear reed on a MkII.
The red circle shows the missing SMD resistors which are present on a MkI, paralleled with the 3 command reeds (integrated into the MKII chip).
The blue circle shows the missing SMD resistors which are present on a MkI, for light-sensor purposes (integrated into the MKII chip).

Here's a picture of the other side of the board:


The red circle shows the missing trimmer (the MkII is user adjustable) and the green circle shows the missing rear reed.

The MkIV is physically very similar to the MkIII, but as mentioned before has a square or encapsulated IC (not rectangular). Unfortunately I couldn't get any good images of a MkIV, but I've seen several PCBs used, including both the single sided and double sided PCBs (same as used for a MkIII).

Apologies for my crap photos. My camera skills are getting worse
Anyway, I hope this helps someone.
Rgds.

[azimuth_pl]

Many thanks, so the Mk2 is a reworked Mk1 whereas the Mk4 is a slightly upgraded Mk3.
These tiny differences make it practically impossible for most people to differentiate these modules.
In most industries you would have a clear naming convention for product generations or releases but here you need to have detailed expertise to tell from a quick glance.
It appears that I have a Mk4 after all with a white ceramic chip package but except this it all looks the same as a Mk3 (late or early).
This is awkward as open wirebonded chips (covered with enamel or silicone) came after those ceramic or plastic packets as the open circuits were cheaper to make.
Hence I'm puzzled why a later Mk4 has a ceramic packet chip?

If the main difference for a Mk2 is a missing trimmer than I have these as well as shown below.

Having a big bunch of parts from Barry in different states of condition I was assuming that most of them have been tampered with and trimmers were removed.
Now I know the nitty-gritty so will need to shoot new pics for my site :) Thanks