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Date
Re: Hints on removing burned tantalum residue
Dave, This looks way better, and might now work, but if it was mine I would clean on it some more. Looking at your hi res photo, there is still some crud around the anode of CR8, around the pin 1 and
By Kurt Swanson · #104675 ·
Re: Hints on removing burned tantalum residue
Hi Kurt, Thanks for great suggestions. I tried the following on the board and am ready to replace capacitor and start testing. 1) Isopropyl Alcohol and Q tip. Mixed results. 2) Xylene (goof off) is
By Dave Miller · #104674 ·
Re: Optiion upgrade HP 8753C/B (CRT Focus)
I've seen reports of bad trimpots on the XY board causing display issues on the 8753A/B. However I had a B with CRT issues and didn't find any bad pots. It did respond well to CRT rejuvenation and I
By Roger Henderson · #104673 ·
Re: Optiion upgrade HP 8753C/B (CRT Focus)
In the future, clean the boards with 100% alcohol and blow dry with compressed air. Best to wash off with de-ionized water but the alcohol alone will work.? Do a final rinse with the alcohol after
By [email protected] · #104672 ·
Re: 334A
I could help you with that.? Can you tell me the problem?? Is it just the oscillator or the receiver/analyzer or do you not know? George Hnatiuk EMAIL:? ghnatiuk@...
By [email protected] · #104671 ·
Re: Hints on removing burned tantalum residue
Dave, I do quite a bit of work on IFR service monitors, and have seen this problem many times, both with tantalum and aluminum electrolytics.? I use alcohol and toluene as solvents, and find that I
By Kurt Swanson · #104670 ·
Re: Anyone out there fix a partially working 334A I need desperately to get it up and running!
I'm sorry Michael, I misremembered. Before I looked in the manual, I remembered lamps, of some sort, and CdS photoresistors, and it registered as a choppers. It is actually a Wien Bridge. Three of the
By Chuck Harris · #104669 ·
Re: Anyone out there fix a partially working 334A I need desperately to get it up and running!
Collective wisdom, y'all. Stay safe...now that Jzonsson de Peffel also got ill, I am starting to worry a bit. To me, he appeared as the pinnacle of a healthy happy strong man... With best regards Tam
By Tam Hanna · #104668 ·
Re: Anyone out there fix a partially working 334A I need desperately to get it up and running!
The 334 has an Automatic Nulling (A6 board) circuit which uses lamps and a single detector. I see no chopper.
By Michael A. Terrell · #104667 ·
Re: Anyone out there fix a partially working 334A I need desperately to get it up and running!
I haven't used it in a while, I've been using a leader LDM-170 but feel more confident in triusting the 334A. First problem is that you can't "Set" anything unless you have an extremely high voltage
By Steve · #104666 ·
Re: Hints on removing burned tantalum residue
Guys, Just in case it helps, the names Marconi Instruments / IFR / Aeroflex / Cobham / Viavi are all historical parts of the same company from 1998 onwards. With regards to IFR, this operation was/is
By nigel adams · #104665 ·
Re: Hints on removing burned tantalum residue
Hi Roy, /g/Marconi-Test-Instruments I have been getting some good information there. Dave wrote: -- 72 de Dave VE7HR
By Dave Miller · #104664 ·
Re: Hints on removing burned tantalum residue
Hi Dave: If you could post the links you found, that would be great. There appears to be many things associated with the names IFR and Aeorflex Cheers and best wishes. Roy
By Roy Thistle · #104663 ·
Re: 427A volt meter
I didn't mean to sound critical but I think I did, my apologies. The lack of mercury cells is a PITA. Lots of stuff used them and its often hard to find a substitute.
By Richard Knoppow · #104662 ·
Re: Anyone out there fix a partially working 334A I need desperately to get it up and running!
Thanks, all! I forgot about the Auto Null function.
By Jeremy Nichols · #104661 ·
Re: Hints on removing burned tantalum residue
What a mess and unfortunately it happens. In addition to the various cleaning hints at least with nicad batteries I have found they do leave conductive stuff. Even though the boards been cleaned. In
By paulswed · #104660 ·
Re: 427A volt meter
excuse my mistake, I have done restoration 427A and 204B side by side on the table. The 22.5V Battery is correct. Can be swapped by 2 pcs of 9V Blocks lithium for backup light , they deliver 10.2V
By Martin M · #104659 ·
Re: Anyone out there fix a partially working 334A I need desperately to get it up and running!
Yes!!! You are a truffle pig! Tam With best regards Tam HANNA Enjoy electronics? Join 15k7 other followers by visiting the Crazy Electronics Lab at https://www.instagram.com/tam.hanna/
By Tam Hanna · #104658 ·
Re: Anyone out there fix a partially working 334A I need desperately to get it up and running!
Is it the video on the HP 419 meter? "https://youtu.be/vrmwql2msbU"
By Merchison Burke · #104657 ·
Re: Anyone out there fix a partially working 334A I need desperately to get it up and running!
You are right, there are 3 CdS cells, and two lamps that are used to operate a Wein bridge that performs the auto null function. The last 334 that was in my shop had one bad CdS cell, and the bridge
By Chuck Harris · #104656 ·