HP 8920A/B, 8921A LCD/VGA Out
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Hello to the group,
I know the LCD conversion is nothing new for the 892x series. I recently, thanks to member "DCFluX" mentioning this, added external VGA out the back of my 8920B. I wanted to share to others that if you want to use the 0.1" header on the LCD board and not wire directly to the terminals here's the part numbers for the connectors and pins. I also cut the #2 ground pin and inserted a block in the female connector to add polarization of the connector to avoid "oops" in the future. TE Connectivity 12-Pin Female Connector? p/n: 87456-7 TE Connectivity Female Pins p/n: 87667-3 I then cut a VGA panel mount cable made by Cables2Go p/n: 52096 and took the HP 8920B blank cover plate off the "Option Interface" on the rear of the 8920B and cut/filed/sanded a place to mount the VGA connector to so it looked factory. The VGA cable barely fits through the LCD/CRT cable port. I do need to find a native 640x480 monitor now to complete the setup. The 8920B is by far my most favorite test equipment that I have ever used. -Alex, KD6VPH |
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Burt, I think you mean me, not Steve.
The LCD display is better in all ways, nothing to complain about whatsoever, I cannot find one thing I dislike. The VGA out was made by hand from some 1/8" Aluminum and a few times of measuring before cutting and filing it to look like a machine made it. I used a VGA PCI card bracket as a template. You have to pull the entire 892x apart to install this FYI. Well worth the money. -Alex. KD6VPH Olympia, WA Links: http://www.simmconnlabs.com/1401/10001.html https://www.ebay.com/itm/134645311739?hash=item1f597c68fb:g:nYsAAOSw92Jdo7tl&amdata=enc%3AAQAIAAAA8L3EF3TzQftdAVBekjCKUZsodPZn9U%2BbcltzNcSGEel3eGacOGSJTv2yIndtBjS9JIYSspAahv5dXVL1XCxXkzMy7wZuKf21%2FOsQQdyPgoMDIlPzPDbT0BbMcuNnbYpn%2FBm%2BeKyVo5ViaVz7GxqRU%2BZQVOnUCq5d0Ga%2FtpHuSxgmBNCN40OyhWFKwKWLOIoXa5KUMcKZg1uNDOzA1UWYdRS28Q%2FcH4sYtjAS1vrEZKuLXtBTIWkwTWqlsFX%2BMQcd8GhbtEIf3rqYrl0LF81wAKaAmx71gmvuF3MspRnNCLp05Bm2h92yIx3Pj1hKV9bhaQ%3D%3D%7Ctkp%3ABk9SR_ici8WwYg |
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Alex,
Yes, I did mean "Alex."? :) Yes, your VGA bracket came out looking like a machine stamped insert.? My big concern is that from certain look angles it might make it hard to see. Where did you get the LCD kit?? Please post a link if you can.? I see one advertised on eBay and was wondering if that's the one you got? Thank you, Burt, K6OQK |
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Hello,
From memory, and having done 2 of the conversions, it's pretty straightforward.
I probably went overboard in writing this reply, but I thought I would be as detailed as I could remember.
If you are doing this I would suggest re-capping the power supply while the unit is torn apart.
Another item to possibly change is the memory battery.
May want to blow out and/or clean the cooling fan too.
I would also re-secure the internal speaker.
?
My list of tools needed for install of the LCD. ?4mm wrench (3/16¡± wrench is a little big but works) 5/16¡± wrench 15/64¡± wrench 5/8¡± deep socket and ratchet 5/16¡± deep socket and ratchet 5/32¡± Allen Wrench 1/16¡± Allen Wrench 0.050¡±Allen Wrench T15 Torx Wrench T10 Torx Wrench #1 Phillips Screwdriver Scissors X-Acto Knife Goo-B-Gone Isopropyl Alcohol Paper Towels Double sided sticky tape to install the speaker back in the holder -- mine was loose because the foam was deteriorated All nuts have to come off the BNC connectors and N-connector.
The multifunction knob and VOL/Sql knobs must come off.
The connector on the backside of the N connector on the front will still be attached -- will need disconnecting, along with the wire harness from the front panel.
The BNC input assembly (cannot remember the name of it at the moment) must come out completely.
You'll need to pull the RF Shield off of the old CRT and re-use the harness, To be able to unplug the harness from the main board you will need to remove a couple modules.
When you have to install the black fuzzy tape that comes in the kit make sure you cut all ends so the do not overlap, and ensure that you do an extremely nice job on this part as anything that is not covered or overlaps you will be able to see thru the front panel when looking at the LCD -- get help if you don't have steady or clean hands.
You will need to solder a supplied SMD resistor in parallel with a pre-existing resistor.
One word of caution: when you pull the front panel apart to remove the CRT plastic/mica/glass off do NOT overtighten the screws underneath the bezel when you put it back on. They should be secure not tight!
If you overtighten the screws you will cause distortions in the clear shield that will annoy you.
Also, before installing the LCD ensure that the clear protective shield is lint free or cat hair free.
I disassembled mine on the kitchen table with a soft blanket and used a pillow to prop it up.
Keep the cat or and super fuzzy animal away, lol.
Have fun,
Alex, KD6VPH
Olympia, WA
On Mon, Jul 24, 2023 at 11:43?AM David Dowler <dave@...> wrote:
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One other thing to mention:
When you pull of the front panel assembly off be extremely careful with the power button rod -- I taped mine with polyimide tape to the unit itself in several spots and left it attached.
If you go to remove the power supply or do the LCD conversion I would definitely not try and disconnect that power switch rod. They get brittle with age and therefore need to be treated very gently.
Alex
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opelgtalex
Burt K6OQK