HP 5335A Timer / Counter - Anything i should know?

[orin]

If you have the DC fan, it's likely that the contacts on the relay socket have opened up.  See the service note in my post above.  The relay socket is a 27E213, Digikey part number PB806-ND.  If it is the relay socket and you do the modification in the service note, you probably don't need a new relay; I'm still using my original relay.  Anyone with a 5335A should make sure that this modification is done and switch to a DC fan.  The 5V supply relay socket contacts get hot, fatigue and eventually, when they cool down, don't make contact with the relay any more.

Thanks, my relay seems to be OK. However removing it shows a black heat mark on the socket, presumably where the 5V passes through. Thanks for the service note, I must give it a go.

The HP part for the relay is 0490-1172. Printed on the side is the code R10A-E1-X6-V430, and a date code 7923. ebay shows loads of R10-E1-X6-V430, is the R10 2A relay and the R10A 5A then?

Regards,
John

Sorry, R10-E1-X6-V430 won't work.  It is a 6PDT relay and wouldn't even fit the socket (18 contact pins) whereas the original R10A is a 6PST relay (12 contact pins).

The V23154-D0721-B112 is a 6PST 2A relay that might work - the contact arrangement appears to be correct.  Onlinecomponents.com have a couple available, but $50 each.  You'd definitely need the service note modification as I measured the current on the 5V supply at up to 2.2A.

Orin.

[Wim13]

I finally got around to working on my 5335A, the service manual is a must have. The input board is the 'A3 Amplifier Buffer assembly (05335-60003)', I replaced the big blue tant caps (22uF) with new 35V parts. It now powers up and the front panel / processor / display appear to work, but it is not working as the PSU voltages are still not right. I get:

-15V output = +0.7V
+5V = 5.07V
+10V=10.0V
+15V=15.7V
-5.2V=+0.6V
+3V=3.0V

So problems with the -15V and -5.2V rails, which appear to be independent. Any tips please?

Regards,
John

Replace the -15V regulator by a 7915, the -5 volts is depended on the -15V.
because of the op-amp that is in line with the -5 V

[1980s_john]

Replace the -15V regulator by a 7915, the -5 volts is depended on the -15V.
because of the op-amp that is in line with the -5 V.

Thanks, I've started removing / unplugging boards to get to the A1 Power Supply board. With A3/A6/A9 removed, the unit now brings up -15V and -5V but only intermittently  . It may be a failing -15V regulator, I see someone has been there before me and a 7915 is already fitted.

I will try and measure the max. current available on -15V and -5V with no boards plugged in, then replace the 7915 and measure max current again. I will replace the fan with a 24V one and rewire the 5V at the same time (currently have a 115V fan fitted and working fine).

No more progress for a few weeks, I wish everyone a Happy Easter!

Regards,
John

[Vgkid]

Does the fan blow into the unit, or out?
Also is it safe to go with a 32cfm fan(26db), or go with the updated 36cfm(29db) fan. Mines starting to get loud.

[PE1RKI]

mine blows out.
i dont mind the noise unless the fan is breaking down or rattling, then i will replace it with a simular one.

[Vgkid]

Thanks, it is starting to get loud. I will most likely get a new one, and fix the old one.
Also, can someone take a picture of the standby led mounting. I just have a hole where the led should be. I have opt 10 installed.

[Vgkid]

Oh no...
powered it on today,noticed that the display stopped updating, reboot not reading my input. Checked the input on my scope, then ran the self test error 7.0. hooked the timebase out to the scope, i see a nice 10Mhz signal.
Crap.

[PE1RKI]

service manuals: 
http://www.ko4bb.com/manuals/index.php?dir=HP_Agilent/HP_5335_Universal_Counter/HP_5335A_Operating_and_Service_Manual_%28hi-res%29

[orin]

Oh no...
powered it on today,noticed that the display stopped updating, reboot not reading my input. Checked the input on my scope, then ran the self test error 7.0. hooked the timebase out to the scope, i see a nice 10Mhz signal.
Crap.

Check your relay socket.  The first symptom is having the instrument start to act goofy.  See my previous posts on the subject.

[Vgkid]

^^^ Will do, as it passed 7.0, and failed at 7.3 today.
how do you remove the metal clip holding in the relay, mine doesnt want to budge.

[Vgkid]

So I reseated the relay, and lost all front panel functionality,rocked it, and everything worked. All test passed.
Also found out that option 40 is installed(wondered why there so many relays on the A2 board, when there should only be 1.), wish it was the prescaler though.

[orin]

So I reseated the relay, and lost all front panel functionality,rocked it, and everything worked. All test passed.
Also found out that option 40 is installed(wondered why there so many relays on the A2 board, when there should only be 1.), wish it was the prescaler though.

Similar to what mine did - fan came on, but no display.  I disturbed the relay and it started working.

It's time for a new relay socket... part #27E213, PB806-ND from Digi-Key; Mouser and onlinecomponents.com have them too for $2 or so.  Easy enough to replace with a decent desoldering tool.

The bad socket contacts should be obvious, so you could try bending them back a little but it's just a matter of time before they fatigue again and open up.

I'd consider trolling ebay for a 'dead'* unit with the prescaler if you really want the third channel, but it's probably cheaper to get one of the chinese 2.7GHz counters, open it up and disconnect the timebase output...

*fan comes on, no display would be a good bet!

[Vgkid]

Already ordered the socket, I think I would rather just buy/make a /10 prescaler.

[Vgkid]

I was trying to dig up any information in the A/B rear input. I have 2 BNC to sma cables installed. The 2 sma connector portions are just held in plave by a spring metal cable clip not connected to anything. The manual doesn't mention anything, and none of the addendums do either.

[Vgkid]

Necro bump
the "parts" counter came today where is the A4U1b to A4U2b jumper located, that is used for option 10.
Both units appear the same.
EDIT
found the jumper resisyor, was looking for a marked link.

[jmsc_02]

Dear,

Recently I won a 5335a from ebay. I've tested inputs A & B and seems ok.

It's a unit from 1982, I know it by the date of the IC's because the serial prefix has been deleted for someone in the past
Also, the unit has 4 sticks saying "Option 010, 020, 030 & 040". Looking outside & inside I see the OXCO & the cards for the  Voltmeter & Input C but I can not see the 040 opt. I need to study the manual to discover it because I do not find anything commented on this thread.

 a pictures of the unit & I have a question:

Who is lying, the 33210A or the 5335A? (there is a continuous offset of 1,2ppm on frequency measurements)

[Vgkid]

Option 40 is installed. Notice how many more triggering/input buttons are installed compared to the non opt 40 units

[agronaught]

I've enjoyed having my 8335. 

One question though, when the inevitable tantalum failures happen, are you replacing with axial tantaliums or other?

Ive not managed to find a suitable source for these components. 


Sent from my Nexus 5 using Tapatalk

[Vgkid]

I dont think that the axial tants are of the wet slug variety, so you can replce them with uprated radial ones.

[Vgkid]

Does anyone have the size of the back power input connector, or are they almost universal for a given style. I nitifed that my frequency jumps have started appearing again.

[DimitriP]

"Almost universal" would  almost be the correct description. You might have to take it apaaaht before you decide which one from the 1500+ available to order from Digikey

[Vgkid]

I figured that much. Now to place another order, and take it apart again.

[jmsc_02]

Option 40 is installed. Notice how many more triggering/input buttons are installed compared to the non opt 40 units

Thank you! I noticed that seeing the manual, but gave no importance...   

[timb]

Basically, with OPT40, the trigger levels are set with DACs, instead of directly from the pots. (The pots are still there, only the MCU reads them and makes changes via the DACs.)

This allows you to remotely set the trigger level via GPIB. It also adds the "Auto Trigger" button, which automatically establishes the correct trigger levels. Another advantage is the ability to vary the trigger level between the peak-peak voltage of the waveform with the knobs. (Normally the knobs would set the trigger level between -5V and 5V, but with this feature on, if you had say a 2Vpp signal centered at 1V, the knobs would move the trigger between 0V and 2V.)

It's the most useful of all the options, IMO. The DVM is the least useful.

By the way, if anyone has the parts for the C Channel option they want to get rid, I'm interested. I need the boards and front panel insert/wiring. (I could also provide a blank insert to replace it if it's being stripped out of a working system.)

I'd like to retrofit my unit with this option, but haven't had much luck finding the parts.

[sdwest]

Hello all,

I recently upgraded my HP 5335A (S/N 2044Axxxxx) from the standard internal crystal to the 18011-60111 OCXO (Option 010).  My unit came equipped with the standard oscillator crystal, but with a card edge connector for the OCXO already built into the A4 board. The two mounting holes for this assembly were pre-drilled in the board.  The correct service manual for this serial number is 05335-90021, which states that the correct OCXO for this SN is 18011A.  Mine was a 18011-60111, so that's the one I installed. 

Jumper W1 on circuit board A4 must first be removed in order to enable the OCXO operation.  This jumper looks like a 1/8 W resistor, but the parts list shows it as a 22 gauge wire jumper.  I carefully cut and lifted one end of this jumper. 

The 10 MHz crystal should then be removed in order to avoid any possible interaction with the new OCXO.  This crystal is in a TO-5 case (HC-35/U Mil) and has 3 leads, just like a TO-5 transistor.  After much probing around in there, I discovered that the crystal was NOT soldered in, it is merely pushed into a special socket on the cirduit board.  From the top of the board, I was able to work it up and out of the socket quite easily.  I was able to get the part number for this crystal from the parts list in my manual, and did a Google search.  I located another piece of equipment that uses this same crystal, and this manual listed several manufacturer sources for it.  The Bliley Crystal website had the specifications for it, the BK3-1B-10MHz, and I am attaching a .pdf of those specs for anyone interested. (Note: the socket for this crystal is easily mistaken for a triangular grouping of solder blobs.  A closer look reveals tiny holes in the center of each blob, to accommodate the crystal leads.)

I first installed the older 10544A OCXO which also worked just fine in my counter, but since I also had the more stable, newer 18011-60111, I settled on that one.

I want to thank Dr. Frank (this Forum) for his kind assistance in this project.  I wish to also thank EEV contributor max_torque for the photos contained in his post of May 23, 2014 regarding the HP5335A.  I took the liberty of re-using crops from two of these photos of board A4 to help illustrate this project.  I hope you don't mind.

Best wishes to all,

Wade
NW IL