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  1. HP-Agilent-Keysight-Equipment
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HP 5245L counting/gate problems

 

I have several of the HP 5245L counters and until recently, had at least one working. Now it seems that the last “working” counter I own has gone belly up.
Two of them have the same problem, (the gate indicator isn’t flashing and one of the two isn't counting). I have the manual and it gives some trouble shooting points to check but in some cases, it only states there is a problem with a board instead of providing a list of components that could be faulty.
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This appears to be a common problem, at least with two of mine. It may be common enough for one of you experts to have fixed it and remembers what component failed. If so, I would greatly appreciate some help.
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Tom. N5AMA
 

Just an idea: In the case of the gate indicator (a neon bulb): try shining a bright light on it to see if that "fixes" it.
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As for "not counting", I don't know an alternative other than to probe signals to find out where things are failing. Is there a gate signal?
I don't remember if the lowest digit display module is unique, or if it's the same as the 2nd digit. If they're the same, try swapping them with each other.
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Pete
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I just resurrected one.

If the power supply hasn't been re-capped, check the supply voltages first.? In my case every d*** capacitor was bad.? Check back then.
 

Hi Pete,
Thanks for the reply. The neon bulb is working on the start and stop test function. When placed on the start position, the bulb comes on but the counter doesn’t display any counting. All the Nixie tubes are working because when the counter is first turned on there is a number displayed that goes away when the counter is reset.
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There appears to be two problems on that counter. One is it’s not counting and the other is the gate isn’t working.
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The second counter appears to have only one problem. It counts when placed on manual test start and stops counting when placed on stop. When this 5245L is placed in the frequency position, it doesn’t show any gate or frequency response on the display. I’m assuming there is only a gate failure here.
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Thanks,
Tom n5ama
 

OK Scott, it has never been recapped as far as I know. I’ll look into how/where the supply voltages are tested and will probably just go ahead and recap to avoid any future supply problems.
Thanks,
Tom N5AMA
jerzy przezdziecki
 

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You can use the old vintage cans and put a newer, low ESR capacitors inside to keep the vintage look.

Just make a simple pcb to solder the new cap inside and keep the old pins outside.

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Jurek

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From: <[email protected]> on behalf of "Tom Smith via groups.io" <n5ama@...>
Reply to: <[email protected]>
Date: Saturday, 22 February 2025 at 16:00
To: <[email protected]>
Subject: Re: [HP-Agilent-Keysight-equipment] HP 5245L counting/gate problems

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OK Scott, it has never been recapped as far as I know. I’ll look into how/where the supply voltages are tested and will probably just go ahead and recap to avoid any future supply problems.

Thanks,

Tom N5AMA
 

I've seen a few open circuit failures of the 1500uF 15V capacitor in at least 2 of the counters from this series and some HP analog multimeters, other than that the others have been OK, a few of the small ones have been a bit tired.
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For gate light faults, I rebuilt a stripped 5245L using a pile of boards from varoius sources and made some to replace those I couldn't obtain, the pile of boards had quite a lot of faults, the gate light was stuck on with the board I had, a lot of the 2N708/709 transistors on one board were either open or shorted, makes you wonder what happened to it to cause that much damage.?
There is a thread here on the rebuild; https://www.vintage-radio.net/forum/showthread.php?t=205651
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David
 

Hi David,
Thanks so much for the reply! My “spare” 5245L counter started working so until I get the repair on the current non HP gear fixed so I won’t be tearing into the busted instrument until those repairs are made. I’ve never had the cover off the 5245 so don’t know what it looks like in there.
In the meantime I bought a 5300B on epay for a reasonable amount and it seems to be working. It’s a smaller counter but just as readable. It may be more difficult to repair because of the smaller size, but for the time being works.
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Tom N5AMA
 

The 5300-series counters also have the advantage of portability if the battery pack “plug-on” is added.?

Jeremy?
N6WFO?



On Sun, Mar 9, 2025 at 7:11?AM Tom Smith via <n5ama=[email protected]> wrote:
Hi David,
Thanks so much for the reply! My “spare” 5245L counter started working so until I get the repair on the current non HP gear fixed so I won’t be tearing into the busted instrument until those repairs are made. I’ve never had the cover off the 5245 so don’t know what it looks like in there.
In the meantime I bought a 5300B on epay for a reasonable amount and it seems to be working. It’s a smaller counter but just as readable. It may be more difficult to repair because of the smaller size, but for the time being works.
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Tom N5AMA

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