HP Agilent 53131A 53132A 53181A 12.4 GHz option

[VK4GHZ]

Hi all

I am looking at replacing my HP 5315A universal counter (with 1.3 GHz option) with either a 53131A or 53181A.
I'm leaning towards a 53181A because I don't need the extra measurement functions of the 53131A.

Just after a good basic counter that can work to 11 GHz.

And then again, there's the BG7TBL FA-2 counter that now goes to 12.4 GHz.
I'd have one of those already if it weren't for the tiny display and the pointless last four digits.


I'm impressed with the Cojotech HP/Agilent 531xxA prescalers, but only has 3 GHz and 8 GHz variants, and I find the "Channel 3 Guide" does not discuss the basic 225 MHz counters (ie; never fitted with any prescaler options) and any upper measurement limits that I believe can be coded into the U14 EPROM.


I notice that BG7TBL are now producing 12.4 GHZ prescalers for the 531xxA counters.
These are a recent thing, with the signature date on the board, these being '2019-11-14'.

https://www.ebay.com/itm/12-4G-option-frequency-counter-OPT-for-AGILENT-HP-53131-53132-53181/274130156096

https://www.ebay.com/itm/12-4G-Option-Frequency-Counter-Meter-For-AGILENT-HP-53131-53132-53181-dt55/174124120434

I'm fully across setting the scale to 4.0 in the math function, but can someone translate the Chinglish on these listings please;

attention:used this option,should be install 3G option,can test 2.0G signal.

Note:
- Please install 3G parts to your frequency meter first before applying our product, so that 2.0G signal can be measured.

Huh?
"3G parts"

Is this referring to the 030 option?
Wouldn't this be removed to make way for a 12.4 GHz board?

Although these BG7TBL products can be a bit hit & miss, has anyone fitted one of his 12.4 GHz prescalers to a bog standard HP Agilent 531xxA 225 MHz counter?

[jadew]

Hey,

Thanks for the e-mail!

I was kinda sleeping on this, because I don't have the documentation/video presentation/etc ready, but I have a 10 GHz option ready that works fine up to 11 GHz and with some limitation to 12 GHz.

It was meant to be a 12 GHz option, and it could have been, but after a couple of prototypes I realized that I can't take it there while retaining some of the key specifications, and without increasing the cost to what I consider to be too much.

Like I said, I don't have any documentation available at this time and only one prototype available, but I think I can start selling it within one or two days, since I'm ready for production otherwise.

In contrast to the chinese options, which I also noticed (they appeared a while after I announced my intention to develop a 12.4 GHz option):
- My option works directly, no extra scaling necessary.
- The maximum input rating is +27 dBm, ±35 V.
- Frequency of operation goes down to 100 MHz.
- Every board gets thoroughly tested and characterized.
- It will come with a high quality SMA connector, for the regular counters (255 MHz, 1.5 GHz and 3 GHz ones), https://cojotech.com/sma-bblk-2, or a high quality N-type connector for the ones that were originally fit with N-type connector (5 or the 12.4 GHz option).
- 2-year warranty.

I don't have typical data at this time, so please don't take it as such, nor as an indication for the minimal specifications, but this is what I measure on the prototype on my bench:

Code: [Select]

Freq (MHz)   Sensistivity (dBm)
100         -22 dBm
200         -30 dBm
500         -37 dBm
1000        -41 dBm
2000        -43 dBm
3000        -44 dBm
4000        -40 dBm
5000        -37 dBm
6000        -36 dBm
7000        -34 dBm
8000        -26 dBm
9000        -29 dBm
10000       -27 dBm
11000       -16 dBm
12000       -14 dBm

While the maximum input power is +27 dBm, across the board, the maximum input sensitivity is specified to +10 dBm (limited by signal generator), and the reason I'm not specifying this option above 10 GHz is because after 11.3 GHz, the maximum input sensitivity starts to drop slowly and reaches +2 dBm at 12 GHz.

Regarding the Channel 3 Guide - thanks about that, I'll have to clarify the text. The 225 MHz counters are actually the same with the 3 GHz ones, and they have no firmware limit.

Cheers

Edit: Increased exposure in one picture and removed a redundant word.

[VK4GHZ]

Hi Razvan

Thank you for picking up on this topic. 

I was kinda sleeping on this, because I don't have the documentation/video presentation/etc ready, but I have a 10 GHz option ready that works fine up to 11 GHz and with some limitation to 12 GHz.
.
.
.
While the maximum input power is +27 dBm, across the board, the maximum input sensitivity is specified to +10 dBm (limited by signal generator), and the reason I'm not specifying this option above 10 GHz is because after 11.3 GHz, the maximum input sensitivity starts to drop slowly and reaches +2 dBm at 12 GHz.

I wrote 12.4 GHz only because of the original OPT 124's specified upper limit.

In real world use, there is a market out there among ham radio operators who, like myself, are on the 5.7 GHz and 10 GHz microwave bands.
A lot of these guys have will already have or appreciate getting one of these HP counters.

By the looks of your table above, sensitivity is good to 10000 MHz.

The 10 GHz ham band center of activity is 10368 MHz.

What is the sensitivity of your prototype at 10368, and say 10400 MHz?

Above 10400 MHz I doubt many hams would really care, so I wouldn't worry too much about that.
Those that might worry should probably be looking at a 20+ GHz counter anyway.

Hams with 24 GHz transverters often use an LO freq around 11-12 GHz (which is then doubled), so even if the counter's front end is a bit deaf, making any measurement at 12 GHz should be considered as a bonus!

Regarding the Channel 3 Guide - thanks about that, I'll have to clarify the text. The 225 MHz counters are actually the same with the 3 GHz ones, and they have no firmware limit.

Appreciate that, as the eBay lucky dip is always a concern.

Just to clarify, a standard 225 MHz 53181A with no optional 2nd channel will have no firmware limit like a standard 225 MHz 53131A with no optional 3rd channel?


I think you'll be on a winner here, compared to the vague Chinese crap on eBay that comes with little or no specifications.

[jadew]

Hey,

What is the sensitivity of your prototype at 10368, and say 10400 MHz?

I'm not in my lab now, so I can't get the exact value at 10368 MHz, but at 10350 MHz it is -20 dBm and -18 dBm at 10400 MHz.

Just to clarify, a standard 225 MHz 53181A with no optional 2nd channel will have no firmware limit like a standard 225 MHz 53131A with no optional 3rd channel?

That is correct, yes. As far as I'm aware, only the 1.5 GHz and the 5 GHz ones were firmware limited, as they were using the same 3 GHz and respectively 12.4 GHz options, that were present on the non limited variants.


Cheers

[Helix70]

What will you do with you 1.3Ghz option for the 5315A?? I have one of these counters, and am missing the 1.3Ghz option. Are you interested in selling it?

Josh VK4JNA

[VK4GHZ]

Hi Josh.

PM sent about that.

Off topic, but you may be interested in some HP 5315A mods I have done;

http://vk4ghz.com/hp-5315-ext-10-mhz-ref-mod-2/

http://vk4ghz.com/grafting-a-fluke-tilt-bail-onto-a-hp-5315a/

[jadew]

Alright, first batch is done and up for sale, with a limited-time 10% discount.

Datasheet: https://cojotech.com/media/datasheets/HPO-100%20-%20Datasheet.pdf
Product page: https://cojotech.com/hpo-100

As you'll see from the datasheet I'm only specifying it to 10 GHz, but as discussed above, it extends past that, but that is not guaranteed in any way and the maximum input sensitivity (not the damage level) gets lower as the frequency increases. I might demonstrate all this in a video soon.

Also, I wanted to mention that an S variant is possible, which would have higher sensitivity (5 to 10 dB), but at the cost of triggering constantly. The regular version doesn't (I think that's another difference between this one and the chinese stuff). So if anyone is interested in that, I can make them on request, at no extra cost.

[bson]

Alright, first batch is done and up for sale, with a limited-time 10% discount.

Order placed!

[jadew]

Order placed!

Thank you! I will dispatch it on Monday.

[EV]

I placed order also! 

[jadew]

I placed order also! 

Thank you!

That was the last one.

Edit: I enabled preordering for anyone still interested. Lead time: 1-2 weeks, but qty will be limited.

[EV]

I got the board today.  It works fine from 60 MHz up to 8 GHz and maybe over it but I can not go higher with my generators.

I placed order also! 

[jadew]

I got the board today.  It works fine from 60 MHz up to 8 GHz and maybe over it but I can not go higher with my generators.

I placed order also! 

Glad to hear that it's working.

I don't know if you caught that, but at the time when I sent you the link to the installation instructions, there was a part missing about tightening the screws It's fixed now, but in case you thought they have to be left loose - they shouldn't.

[EV]

I tightened the srews of course. I did not read much instructions, it was so easy.

... in case you thought they have to be left loose - they shouldn't.

[jadew]

I tightened the srews of course. I did not read much instructions, it was so easy.

Heh, that's good. I was worried because I put a lot of stress on not warping the board too much, and was afraid that it read as if the screws can't be tightened at all.

[EV]

I measured the sensitivity of this HPO-100 with HP 8642A signal generator. It goes only up to 1 GHz and its calibration date has expired.

Freq (MHz)   Sensistivity
   50             -17 dBm
  100            -24 dBm
  200            -30 dBm
  300            -34 dBm
  400            -36 dBm
  500            -38 dBm
  600            -39 dBm
  700            -40 dBm
  800            -39 dBm
  900            -41 dBm
 1000           -40 dBm

[jadew]

@EV, my test report shows similar values for your board, ± 1 or 2 dB at some frequencies, but it sounds about right.

Be careful about the 50 MHz result tho. At that frequency it doesn't operate correctly around the -4 dBm power. This is a design limitation and not particular to your board, and it's why I'm only specifying it from 100 MHz up, but I know how it can be misleading.

[EV]

I have no problems with HP 8642A signal generator on any signal level I tried between 36 - 100 MHz (sine wave).  On 36 MHz sensitivity is -13 dBm.
With WB-SG1 Wideband Signal generator there are problems between 36 - 80 MHz square wave signal. Its level is 0 dBm. Here is picture of its 50 MHz signal:

Be careful about the 50 MHz result tho. At that frequency it doesn't operate correctly around the -4 dBm power. This is a design limitation and not particular to your board, and it's why I'm only specifying it from 100 MHz up, but I know how it can be misleading.

[jadew]

@EV, that's good then. The deviation I measured was very small to begin with, so it's possible it's not there for your board.

[Stray Electron]

Hey,

What is the sensitivity of your prototype at 10368, and say 10400 MHz?

I'm not in my lab now, so I can't get the exact value at 10368 MHz, but at 10350 MHz it is -20 dBm and -18 dBm at 10400 MHz.

Just to clarify, a standard 225 MHz 53181A with no optional 2nd channel will have no firmware limit like a standard 225 MHz 53131A with no optional 3rd channel?

That is correct, yes. As far as I'm aware, only the 1.5 GHz and the 5 GHz ones were firmware limited, as they were using the same 3 GHz and respectively 12.4 GHz options, that were present on the non limited variants.


Cheers

  I have been offered a 1.5 Ghz HP 538181A with the 010 High Stability time base. If I understand your statement correctly then the only change that would be needed to bring it up to 3 GHz is a software change. Do you know what would be needed to change the SW?

[bson]

Got mine too!

I can only test it up to about 3.5GHz since that's the limit for my HP 8133A pulse generator, but that all works fine.  It's nice to replace the BNC input of the OEM 3GHz board with an SMA connector.  I didn't check how the jitter compares to the OEM, but it's quite possible this board performs better also at frequencies where it overlaps the two regular channels on my 53131A.

I also didn't check the instructions; installation is trivial.

Good stuff!

[jadew]

I have been offered a 1.5 Ghz HP 538181A with the 010 High Stability time base. If I understand your statement correctly then the only change that would be needed to bring it up to 3 GHz is a software change. Do you know what would be needed to change the SW?

I didn't need to do it myself yet, but I have come across several discussions on the topic. You will have to pull out one of the ICs on the mother board, read it, patch it, and put it back. Don't know what keywords to give you, but I'm sure google's AI will be more than willing to help

Got mine too!

I can only test it up to about 3.5GHz since that's the limit for my HP 8133A pulse generator, but that all works fine.  It's nice to replace the BNC input of the OEM 3GHz board with an SMA connector.  I didn't check how the jitter compares to the OEM, but it's quite possible this board performs better also at frequencies where it overlaps the two regular channels on my 53131A.

I also didn't check the instructions; installation is trivial.

Good stuff!

Thanks for the update! Was wondering if you got it working.

I agree about the SMA. It's one less adapter that I have to use.

[VK4GHZ]

Hey,
  I have been offered a 1.5 Ghz HP 538181A with the 010 High Stability time base. If I understand your statement correctly then the only change that would be needed to bring it up to 3 GHz is a software change. Do you know what would be needed to change the SW?

Found on Groups IO:


Ok, I here is the updated process which includes the upgrade/downgrade offsets & values for the 53181A & 53132A.  They're identical values, so they SHOULD work with a 53131A.

 1) Remove the existing 3rd channel, if it exists
 2) To add 5/12GHz module, install Zero Ohm resistor in R334 position (located on underside of mainboard near J6).
     To replace 5/12GHz module with a 3GHz module, remove R334.
 3) Remove U14
 4) Read U14 via EPROM burner
 5) Validate that header of data says 'HP53131 is a winner!' (it says this for 53131A/53132A/53181A)
    * Be 100% sure the read is good.  Some unit-specific cal data is on this.  Maybe read it a few times and with
    multiple burners if available.  Verify the checksum doesn't change on several reads.  Place the checksum in the
    filename when you save it, so you know what it is supposed to be in the future.

 6) Install socket in U14 location.  Insert the original unmodified EEPROM into the socket and power on
    to ensure there are no errors (leave the 3rd channel OUT during this test).  You just want to make sure
    the counter can fire up without errors.   Once you're sure the socket installation is working well, remove the
    EEPROM and proceed.

 7) Using a hex editor of your choice, change the following offsets to the indicated values:

For 12GHz module:
Offset 0x01, Value 0x30
Offset 0x1b, Value 0x03
Offset 0x1c, Value 0x04
For 3GHz module:
Offset 0x01, Value 0x2F
Offset 0x1b, Value 0x02
Offset 0x1c, Value 0x01

  Erase the factory EEPROM, or use another equivalent one, and burn the new version with the changed bytes.
 9) Insert modified EEPROM in the newly installed socket
10) Install the appropriate 3rd channel prescaler (12GHz/3GHz)

Power On and watch for errors.  If any errors come up, the ROM info is bad or not being read correctly. Re-socket the chip, re-burn, check solder job, etc.  There should be NO errors.

Not entirely sure why one would want to do this, but the following values are to digitally limit the 12GHz prescaler to 5GHz:

Offset 0x01, Value 0x2F
Offset 0x1b, Value 0x02
Offset 0x1c, Value 0x04

Now, if you have a 1.5GHz or 5GHz optioned unit, simply changing the EEPROM values to the 3GHz or 12GHz values (respectively) will upgrade that unit without any additional hardware

Happy Counting!

Colby
K6RKE

[Helix70]

Hi Josh.

PM sent about that.

Off topic, but you may be interested in some HP 5315A mods I have done;

http://vk4ghz.com/hp-5315-ext-10-mhz-ref-mod-2/

http://vk4ghz.com/grafting-a-fluke-tilt-bail-onto-a-hp-5315a/

Thanks,

My bail is working, and I have fitted a 10Mhz Movion OCXO module to a PCB from amc184, designed for the 5315A/5316A. When I check with my GPSDO, it is still within 0.1Hz after 12 months. I really like the 53131A/53132A/53181A machines, especially with 3+ Ghz channel upgrades, keeping my eyes open for a great price.

[Stray Electron]

   Thanks Colby!  One question, can the 1.5 be upgraded to 12.4GHZ by SW alone?  I thought that the 1.5 and 3 GHZ models used one prescaler board and the 5/ 12.4 GHz prescaler used a different board.  Or is the only difference between the boards RF input connector? (type N instead of BNC).

[jadew]

   Thanks Colby!  One question, can the 1.5 be upgraded to 12.4GHZ by SW alone?  I thought that the 1.5 and 3 GHZ models used one prescaler board and the 5/ 12.4 GHz prescaler used a different board.  Or is the only difference between the boards RF input connector? (type N instead of BNC).

Unfortunately, no. You are correct that the boards are different. The one in the 1.5 GHz and 3 GHz counters goes only to 3 GHz.

Edit: Grammar.

[charlyd]

What about an EIP  545A /548A or better 575 / 578 .. serious good counters for good prices   >18GHz >26.5GHz

[Stray Electron]

What about an EIP  545A /548A or better 575 / 578 .. serious good counters for good prices   >18GHz >26.5GHz

   What about them?  I have about 6 of the 545As left.  They ARE seriously good counters but they are full rack mount size and weight about 30 pounds apiece. 

    I really don't need a small portable counter like the HP 53181 but it SO tempting! If I could upgrade it for a reasonable price (like $0) to 12.4 GHz,  I'd be on it on it like a duck on a June bug!

[jadew]

They're back in stock.

Limited qty. available, and the discount is gone.

I also made a little video showing the limitations outside of the 10 GHz range, for anyone interested in performing measurements there. Keep in mind tho, that operation above 10 GHz is not guaranteed at all.

Edit: Below the frequency region that exhibits these limitations, operation above 10 dBm is possible, but I can't test it as part of the production process, which is why the maximum input sensitivity is specified at 10 dBm.

[tchiwam]

I will post it here, as this thread has a lot of interesting information that is still relevant.

I have :
 53181A Option 010 124  SN: KR9120XXXXX Made in Korea
 53132A Option 012         SN: 3546AXXXXX   Made in USA

I wanted to move the 12.4GHz card to the 53132A, but I 1, cannot find the R334 on the 53132A, I did find it on the newer 53181A near J6

I tried it, and the Channel 3 can be selected, but there is no counting being done on the Channel 3. Any idea of the pin or signal jumped By R334 ? 

Oscilators :  This might also be of interest:
Option 010  Crystal 10811-60160
Option 012  Crystal 10811-60211

Jumpers are at the same place, and board seems to be the same. So I guess that someone with a 010 can find the 012 oven alone and make the swap pretty straight forward.

[tchiwam]

One more bit of information....

   If I get this right, the purpose of the R334 0 ohm is to bring 5VDC to J7 pin 7 ?

My 53132A does not have that 5VDC at pin 7

Also the J7 Pin 7  seems to be connected to 53132A-R241, which is totally not connected to the same as my newer 53181A

Anyone here knows how to make the old 53132A take the option 124 ?

 

[tchiwam]

A bit of probing later:

With R334 0ohm on the 53181A

J7 Pin Pin 53181A 53132A 5 +12V +12V 6 +12V +12V 7 +5V 0 8 -12V -12V 9 0V 0V 10 Pull up 5V Pull up 5V Pulled down when Option 124 is present Channel 3 detect ? I am tempted to switch the pin 7 and 10... I will come back to it tomorrow and probably try it.

Edit Pin 10 probably a pull up...

[tchiwam]

And one more update, I found this document 9018-01593.pdf

Pin 7 is the 5VDC and R334 is R335 in the part list...



Seems I have the Rev C of the board, but an early one... 53132-60001 where the R334 seems not to exist...

J7 Pin 9 and 10 are both code to tell the main board what prescaler they have, I assume...