[time-nuts] PTS160 DDS option, was Synthesized Signal Generator query

[gandalfg8 at aol.com]

PTS have always been notoriously unhelpful to anyone aside from original purchasers.

Around 15 years ago I was looking for a PTS160 manual and the UK agents were very helpful, and quite happy to request a price on my behalf, but then came back to tell me they'd been told by PTS they couldn't deal with me.
When manuals did start to become available, as surplus items along with more used PTS units themselves, PTS were very quick to jump on anyone who made copies available from anything approaching a public download site.

Option K, as shown in your serial number, is the 0.1Hz resolution DDS option as per the ordering information on page 30 of the current PTS catalog. This catalog is downloadable from the PTS web site and quite a useful source of information.
I have one with option J, the "inferior" :-) 1Hz resolution DDS version, which the current catalog shows as an unavailable option for the PTS160 although it was in the past.
Also commented in the catalog is that the PTS310 comes with DDS fitted as standard and the manual for that is available, although I'm not sure how similar the circuits might be as I tend to take an "if it ain't broke don't fix it" approach to these and so far have found all my PTS units to be very reliable.The only issues I recall have been items dislodged in transit, that DDS board for example, an obvious afterthought and a less secure fit than normal modules, was one, and a very small left over blob of solder that caused fun when it dropped into a module edge connector was another.
The similar, ish, Wavetek 5120A, manual available, also uses a DDS section but again my previous comparisons focussed more on the standard modules than the DDS sections.

The PTS160 and Wavetek 5120A both seem to derive from the earlier Rockland 5600 and all credit should go to PTS for greatly expanding the range, but they do seem somwhat over paranoid that someone else might jump on their bandwagon.
Nigel GM8PZR
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I had a recent email exchange with PTS. I have a PTS 160 SK01G serial number 1A 8428. The output drops off rapidly below 70 KHz. It doesn?t match the manuals available online as it has .1Hz resolution but without the number of DM modules the manual says it should have. Instead it has a couple of DM modules and another module that apparently performs all the functions of multiple DM modules.

I emailed PTS about the possibility of acquiring a manual that matches my unit and the response was:
?Sorry, don't routinely offer complimentary support or complimentary manuals.

More to the point: PTS 160 has a specified lower limit of 100 KHz, no "fixing" possible to obtain outputs lower than that and not malfunctioning.

If the failure is occurring when setting certain 10 KHz steps but at output frequencies above 100 KHz, we'll need to see the unit and the repair cost for a unit of that vintage is $2500.

If you'd like the unit repaired, feel free to contact us, but we are not able to respond to any other inquiries on how to fix your unit.?

I didn?t ask for anything ?complimentary? and would have been happy to pay a reasonable price for a manual matching my unit. Maybe explaining to them in my email that I?m a hobbyist and not a million dollar a year buyer was not a smart thing to do but I prefer to be upfront when making requests for information. 

If I felt the need, for $2500 I could buy a good assortment of PTS synthesizers on eBay and swap parts to my heart?s content. 

I?ve discovered the output amplifier rolls off quickly below 70 KHz so my unit is working correctly and I just need to switch over to a 3325B for the lower frequencies.

Steve
WB0DBS