Tek 2710 spectrum analiser

[G6EZG]

HI
I have just acquired a 2710  with a fault , hopefully an easy repair
the display has no horizontal scan  it looks ok vertically but all i see is a line
before i start to investigate as anyone come across this fault before

Ivan

[tautech]

Welcome to the forum.

Quick Google found the manuals:
http://w140.com/tekwiki/wiki/2710

There's a few other 2710 repair threads on various forums, use this search: "tek 2710 service manual"

[guido]

Think it contains Signetics PLS chips. Programmable logic like PALs. With the anoying habit of loosing their content...
Unfortunately they are SMD, no sockets iirc.

I have some dumps of the ROMS, PLS etc (from the internet). If you need them, mail me.
In case it is a PLS and you are sure which one, i can decompile the JED file into the equations, so you know what it is supposed to do.

[G6EZG]

Thanks for the welcome and the information
Ivan

[tautech]

Thanks for the welcome and the information
Ivan

Feel free to use this thread as a running documentary of your repair, this kind of record can help others immensely.

[Fraser]

I have a TEK 2710 Spectrum Analyser in nice condition with a power supply fault that I have never got around to repairing. Happy to sell it for someone else to repair or use as a parts donor. I think £100 + postage is a fair price for it if anyone uses interested.

I suspect this will be UK only due to shipping challenges for overseas.

Fraser

[G6EZG]

Hi Fraser
where about in the country are you
I May be interested

Ivan

[Fraser]

Ivan,

Milton Keynes

Fraser

[G6EZG]

Fraser
is the unit dead hence psu fault ?
what will the carriage to hull likely to be ?

Ivan

[Fraser]

History is as follows:

Switching transistors blew

New switching controller fitted
New switching transistors fitted
New Electrolytic capacitors fitted
New memory Lithium Battery fitted (darned expensive !)

Switched on and the inverter stage transistors blew ! They were likely already damaged in the first failure.

The SA was put to one side in disgrace as i have several others that I use. This was soe years ago but it has been stored carefully. I just have no need of it.

Shipping to Hull should not be too bad. Less than £25 with UPS I suspect. I will need to check.

Fraser

[G6EZG]

Thanks for that information Fraser

I will have a good look at mine over the next couple off weeks , and get back to you ,
i just need to decide if mine is worth spending the money on .

regards
Ivan

[Marcel G]

http://www.pa4tim.nl/?p=4522 

Link to repair Tek 2710 spectrum analyzer-service manual.

[Marcel G]

G6EZG

More Info about screen problems Tek 2710 spectrum analyzer.

http://www.edaboard.com/thread158959.html

Regards,

Marcel

[G6EZG]

Thanks Marcel

Regards
Ivan

[grumss]

Hi all,
Yes very old post but i thought i would add my findings to hopefully be helpful to others..

My screen also has gone into the dreaded displaying garbage symptoms.  After spending a lot of frustrating time playing around i think i can put my finger on the problem (mine anyway), digital is certainly not one of my strong points but here goes..

It seems the SA's display pages are changed by pin 7 of U260 (PLS159), this chip is supposed to send a negative pulse to a binary counter (U326). The binary counter counts until the correct page/s is displayed then is suppose to stop.
The binary counter also sends signals to other chips including U308 which controls blanking and "dotenable"! (one of the classic things we all see with the fault)...
What seems to be happening (in mine anyway) is that U260's pin 7 is caught in a near mid state, around 4V in mine- any noise in the circuit is +- on the 4v and sending the page select counter into near constant counting- this seems to be why we see all of these unusual displays....

Now to prove the point, i pulled the pin 7 output up to 5v with a high value resistor- the SA now always boots to a spectrum display which i assume must be default with the initial (000?) binary output from the counter.. no other screen data is displayed but at least i can see a working spectrum..
I experimented with mosfet switching on pin7 to lighten its load but had no success.. I dont think it pulls down at all...

Now all i have to do is find a PLS159, the code and try to program it!  GEEZ!!  (id very very thankful if one of you guys can help)
I dont think the PLS is doing very much looking at its clock, but for me the code would be very difficult to invent..

Hope i have been of help.
cheers, Graham VK3XDK  (grumss@yahoo.com.au)

[giosif]

Hi,

I too am having trouble locating replacement ICs for the different PLS models on the display board of my 2710.
However, specifically for the PLS159, I see someone based in Poland is selling some - https://ebay.us/b4NeOA

With regards to the code, you can find the full list of dump files in a few places: TekScopes@groups.io and KO4BB web site.
This list includes the JED files for the PLS ICs.

Hope this helps!

[grumss]

Thanks giosif- i will have a look... programming these devices may be an issue too for us non digital guys ,,, I hate to see a great SA going to waste though!


One thing that i will mention is that mine had a lot of use here ( for years), it was on for hours during testing when it first started playing up... I heard an electrical "arcing" sound and from that moment on things started to misbehave.. So i suspect many of "our issues" originate from the power supply and  damage the sensitive PLS devices... I have looked carefully at the power supply on mine and still havnt found any issues but i think it may be an intermittent thing..

If the PLS damage is due to power supply "spikes" (as i suspect) it may be worthwhile to put some protection on the most venerable boards (digital storage board No.1)...