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Re: Hints on removing burned tantalum residue

 

What a mess - it really did a number on that board section. I agree that acetone would be a pretty good solvent for some of the char, but unfortunately, it may not clean it all off. Some is likely carbon particles (from burning up the coating) and Ta oxides (from the cap guts) splattered onto (and into) the surfaces, and no conventional solvent will dissolve it. The good news is that even if you can't get it spic and span, any remaining residue probably won't hurt the circuit operation after cleaning and repair.

Besides some solvent action, good mechanical scrubbing should help. I'm not sure if your comment about IPA is a question (will it work?) or a statement (tried and it doesn't work). I'd start with IPA, if you haven't already. Paint thinner or acetone are logical next steps. Acetone may be a little too intense to leave on for very long.

Presuming you don't want to remove the board from the RF assembly, which appears to have its feed-throughs soldered to the board, the trick is to be able to work on board cleanup without getting anything bad into the RF. IPA and acetone would probably be best then, since they're miscible with water and will evaporate quickly, while paint thinner would be a bit messy and slow to depart.

If the board can be readily removed, you have more options such as aqueous washing with detergents, and some gentle abrasive action such as an opaque toothpaste worked with - of course - an old toothbrush, to scrape off the particles that aren't too tightly embedded in the surfaces. Regardless of the solvents and methods, I always use old toothbrushes for scrubbing. Higher intensity solvents may dissolve or degrade the bristles and heads, so you have to work fast in some cases.

Another option, if you have access to the appropriate equipment, is to skip solvents altogether and do purely mechanical cleaning, like with a soda or walnut shell blaster.

Good luck.

Ed
Re: Optiion upgrade HP 8753C/B (CRT Focus)

 

My 8753A had a CRT with low intensity as well as beeing unfocused.
I have not tried to rejuvinate the CRT, but I took the monitor apart and made a deep
cleaning of the HV circuit board. Vacuuming of the electrostatic dust and then
wiping the board as clean as I could with a dampened cloth.
Also the CRT was taken out and cleaned.

The intensity is still low but the focus could then be adjusted to satisfaction.

I guess that leakage currents caused by the dust and dendrites formed
by pollution and moisture in a 30+ year old instrument can be a problem.

Cheers

Ulf Kylenfall
SM6GXV
OT: Help identifying these mixers required

 

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Hi all,

Pocking around one of my junk boxes I happened across a couple of mixers I picked up on eBay I had completely forgotten about.

One is an ADTEC M-10 20, the other is a Demornay/Bonardi DBW-633

I'd greatly appreciate it if anyone has specifications or data of any kind for these devices.

thanks

Tim



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Re: Hints on removing burned tantalum residue

 

¿ªÔÆÌåÓý

Thanks guys,
Good reminder on wooden Q tips. ?
There is also Xylene. (Goof off)
I shall go at it slowly. ?No rush
Might have to wait as it¡¯s sort of hard to just pop over to the local store as many are shut down.?
Might also try Ultrasonic. ?

Thanks
Dave


On Apr 6, 2020, at 10:38 PM, Bill via groups.io <ko4nrbs@...> wrote:

?
Try Acetone.? I use it with q-tips and a rag.? Don't pour it on the equipment as it may melt some things.? Just dampen the q-tip or rag with it.? ?Have good ventilation and no open flames!!? That includes space heaters.
Bill
Re: Hints on removing burned tantalum residue

 

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Make certain it is a wooden steam Q-tip. ?Acetone will melt the plastic ones.

Ken


On 6Apr, 2020, at 11:37 PM, Bill via <ko4nrbs@...> wrote:

Try Acetone.? I use it with q-tips and a rag.? Don't pour it on the equipment as it may melt some things.? Just dampen the q-tip or rag with it.? ?Have good ventilation and no open flames!!? That includes space heaters.
Bill
Re: Hints on removing burned tantalum residue

Bill
 

Try Acetone.? I use it with q-tips and a rag.? Don't pour it on the equipment as it may melt some things.? Just dampen the q-tip or rag with it.? ?Have good ventilation and no open flames!!? That includes space heaters.
Bill
Re: 427A volt meter

 

I¡¯ve got one, it works well. First I suggest checking the power supply for proper voltages and regulation. It might have a filter cap in need of replacement.

Jeremy?
N6WFO


On Mon, Apr 6, 2020 at 10:19 PM Richard Knoppow <dickburk@...> wrote:
??? Its a nice little portable meter. They came out when I worked
for -hp- and I got one for my bench. There was a story about how
it got designed but I've forgotten it. There is a battery only
version and one with an AC supply that also works on batteries. I
made a battery pack for mine using AA cells in holders from Radio
Shack.
??? Adjustment is easy but you need a source of calibrated
voltage (as with any meter). There were some design changes in
the front end, I think details are in the manuals avaiable at
BAMA.? Any modern SS digital meter will bet the thing but I still
like mine and prefer analog meters for a lot of things. I think
there was an RF probe made for it, probably easy to duplicate. I
wish I could remember what else I knew about it but its been too
long. Anyway, I would attempt to calibrate it.

On 4/6/2020 9:14 PM, Paul Bicknell wrote:
> Hi all
>
> Just switched on a 427A volt meter that I rescues a few weeks ago
>
> Just wondering is their any think special about it and is it worth spending
> any time on as it reads low
>
> Paul
>
>
>
>
>

--
Richard Knoppow
dickburk@...
WB6KBL




--
Jeremy Nichols
6.
Re: 427A volt meter

 

Its a nice little portable meter. They came out when I worked for -hp- and I got one for my bench. There was a story about how it got designed but I've forgotten it. There is a battery only version and one with an AC supply that also works on batteries. I made a battery pack for mine using AA cells in holders from Radio Shack.
?? Adjustment is easy but you need a source of calibrated voltage (as with any meter). There were some design changes in the front end, I think details are in the manuals avaiable at BAMA.? Any modern SS digital meter will bet the thing but I still like mine and prefer analog meters for a lot of things. I think there was an RF probe made for it, probably easy to duplicate. I wish I could remember what else I knew about it but its been too long. Anyway, I would attempt to calibrate it.

On 4/6/2020 9:14 PM, Paul Bicknell wrote:
Hi all

Just switched on a 427A volt meter that I rescues a few weeks ago

Just wondering is their any think special about it and is it worth spending
any time on as it reads low

Paul



--
Richard Knoppow
dickburk@...
WB6KBL
Re: Anyone out there fix a partially working 334A I need desperately to get it up and running!

 

I would think that a lot of the answer depends on where you are located. If the meter has to be shipped twice the cost could be very high depending on locations.

Stuart K6YAZ
Los Angeles, USA
Re: 427A volt meter

 

On 4/7/20 12:14 AM, Paul Bicknell wrote:
Just switched on a 427A volt meter that I rescues a few weeks ago

Just wondering is their any think special about it and is it worth spending
any time on as it reads low
I've never put my hands on one, but I checked out the specs a bit. It
doesn't seem particularly noteworthy in any specific way, but it sure
does look like a nice handy all-around bench meter with a nice big meter
face.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
427A volt meter

 

Hi all

Just switched on a 427A volt meter that I rescues a few weeks ago

Just wondering is their any think special about it and is it worth spending
any time on as it reads low

Paul
Re: Option 030 in HP 3708A Noise and Interference Test Set?

 

I can haul mine out of the rack for comparison purposes if necessary. Not sure if mine has any options fitted but doubt it - It DOES have huge handles though-they stick out sideways as well as forwards- which I suspect are not standard but look to be factory fitted.

DaveB, NZ

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Andy ZL3AG via groups.io
Sent: Tuesday, April 07, 2020 15:09
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Option 030 in HP 3708A Noise and Interference Test Set?


Yeah. I think if you can track down the Japanese manual, that might solve the dilemma.

Or a see if the any of the HP Scotland guys on the list can remember what it's all about. :^)

On 7/04/20 2:51 pm, Jared Cabot via groups.io wrote:
Thanks for the file Dave! I'll save it for future reference. :)

I was thinking something to do with Japanese market as you say Andy but there's no mention in the manual from the Keysight website. Maybe I should try to track down a Japanese manual...

There is an option to have some preset reference tone frequencies altered to user specification (with no corresponding option number shown on page 72 of the manual), but the front panel labels look normal, unless they weren't relabelled...
Once the unit arrives in the next day or two, I'll have to measure that to see.
Hints on removing burned tantalum residue

 

Not directly HP related but this is where the knowledge is.
I am starting to repair an IFR-1200S that had an incident.


A 150 uF 15V tantalum went up in smoke.
What is the best solvent to remove the residue on the rest of the PCB. Isopropyl does not take all of it off? Want to get it all clean before I replace parts and continue the repair.
Thanks
Dave?
Re: Ebay seller called m2wave

 

On Mon, Apr 6, 2020 at 04:27 PM, James Stephens wrote:
As he doesn¡¯t allow contact and I am interested in an item he has for sale
Hi Paul: I sent him a message about an item just now, on Ebay¡­ no problem. It's in my sent box, under Messages in My Ebay¡­ so I assume it is at least spooled up on Ebay.
Best wishes and regards.
Roy
Re: Option 030 in HP 3708A Noise and Interference Test Set?

 

Yeah. I think if you can track down the Japanese manual, that might solve the dilemma.

Or a see if the any of the HP Scotland guys on the list can remember what it's all about. :^)

On 7/04/20 2:51 pm, Jared Cabot via groups.io wrote:
Thanks for the file Dave! I'll save it for future reference. :)
I was thinking something to do with Japanese market as you say Andy but there's no mention in the manual from the Keysight website. Maybe I should try to track down a Japanese manual...
There is an option to have some preset reference tone frequencies altered to user specification (with no corresponding option number shown on page 72 of the manual), but the front panel labels look normal, unless they weren't relabelled...
Once the unit arrives in the next day or two, I'll have to measure that to see.
Re: Option 030 in HP 3708A Noise and Interference Test Set?

 

Thanks for the file Dave! I'll save it for future reference. :)

?

I was thinking something to do with Japanese market as you say Andy but there's no mention in the manual from the Keysight website. Maybe I should try to track down a Japanese manual...

There is an option to have some preset reference tone frequencies altered to user specification (with no corresponding option number shown on page 72 of the manual), but the front panel labels look normal, unless they weren't relabelled...
Once the unit arrives in the next day or two, I'll have to measure that to see.
Re: Option 030 in HP 3708A Noise and Interference Test Set?

 

Hi Jarod, me old cobber,


Maybe it's a peculiarity for the Japanese market? Some sort of filter/freq option?

Andy

On 7/04/20 2:02 pm, Jared Cabot via groups.io wrote:
Hi,
I just picked up a HP 3708A Noise and Interference Test Set for a good price (1000 yen :) ) and it appears to have option 030 installed, but this isn't listed in the manual.
I'm wondering if this could be a custom option of some sort? Does anyone know how I can find out what this option is?
I remember seeing a big 'master list' of HP options somewhere recently, but fort the life of me, I can't find it now. I was hoping to find the info in there maybe.
Thanks!
Anyone out there fix a partially working 334A I need desperately to get it up and running!

 

I have an Hp 334A that powers on and appears to function partially but I¡¯m not sure what all could be wrong with it. If anyone fixes these units at a reasonable price I would be interested in having it put back in top notch shape with a good calibration. I restore vintage hifi and I need to get it up and going as quickly as possible.?
Re: 334A

 

I¡¯d like to know if anyone out there can fix a somewhat working 334a and about what would it cost?
Re: Option 030 in HP 3708A Noise and Interference Test Set?

 

On 4/6/20 10:02 PM, Jared Cabot via groups.io wrote:
I just picked up a HP 3708A Noise and Interference Test Set for a good
price (1000 yen :) ) and it appears to have option 030 installed, but
this isn't listed in the manual.
I'm wondering if this could be a custom option of some sort? Does anyone
know how I can find out what this option is?
I don't see it in the big master list.

I remember seeing a big 'master list' of HP options somewhere recently,
but fort the life of me, I can't find it now. I was hoping to find the
info in there maybe.
File sent off-list.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
46881 - 46900 of 151434