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  #61  
Old 09-28-2012, 12:21 PM
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N2IXK N2IXK is offline
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Just snagged a VA62A on eBay for $42.50 from a seller within 20 miles of me. Claimed to be working, and the only thing that looks wrong in the auction pics is that somebody busted off the ground pin on the power cord. Once I get the thing onto the bench, I'll be wanting one of the hacked EPROMs for my unit, as well. Will PM you soon to make arrangements...

Thanks for all the great info on these units! Particular thanks to Phil for hosting all those manual scans! Just grabbed the full set...

Last edited by N2IXK; 09-28-2012 at 02:03 PM.
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  #62  
Old 10-07-2012, 09:11 PM
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N2IXK N2IXK is offline
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Got the unit on the bench over the weekend, and everything seems to work just fine. All the patterns display properly, RF frequencies all nice and stable on a counter, and all the drive signals look good on a scope. Replaced the line cord, and swapped the 3 front panel RCA jacks (30 Hz Servo drive, Video out, and 3.58 MHz drive) for BNCs. Why would they even use RCA phono jacks on this kind of equipment? BNCs are much more rugged with stuff being plugged/unplugged all the time.

How many different accessory units were made for this thing? I know of the NTSC pattern generator and the VCR test unit. Any others?
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  #63  
Old 11-04-2012, 12:42 PM
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UPDATE:

Received the mod EPROM from Dave, and it works great. Opened up the RF range from 35-50MHz to 11-85 MHz with solid PLL lock over the whole range.

Now to install the RF/IF level switch....
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  #64  
Old 11-04-2012, 03:43 PM
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Zenith6S321 Zenith6S321 is offline
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Thats good news! Looks like the old VA62 firmware that the modification is based on has worked in all the VA62A versions tried so far. Be very careful and check over thee RF/IF switch wiring, as it switches +/- supply voltages to control the RF/IF amplifier output sections. Get the wires wrong and it could be bad news!
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  #65  
Old 11-08-2012, 03:46 PM
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Switch installed, and all is working great! Thanks, all!
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  #66  
Old 01-01-2013, 11:08 AM
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Quote:
Originally Posted by Phil Nelson View Post
On request, I posted the VA62A files temporarily on my website.
Thank you for posting the VA62A information, Phil. I just bought one of these units on Ebay and I appreciate your efforts.
__________________
Chris

Quote from another forum: "(Antique TV collecting) always seemed to me to be a fringe hobby that only weirdos did."
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  #67  
Old 07-05-2013, 09:12 AM
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Here here. Likewise for me as well. Thanks for you work.

Quote:
Originally Posted by ChrisW6ATV View Post
Thank you for posting the VA62A information, Phil. I appreciate your efforts.
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  #68  
Old 04-09-2014, 04:22 PM
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Rcr1961 Rcr1961 is offline
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VA62 rom

Quote:
Originally Posted by Zenith6S321 View Post
As an avid reader of these forums I came across Bob's post about wanting a wider frequency range on the VA62. A few months ago I did my first restoration on a 721TS and found out how touchy analog RF generators are to use for a marker generator. I happened to have a VA62 and its schematics which I used to fix its 1MHz reference to the PLL. Back in the day I did some digital design work. So, like Jeremy Clarkson of Top Gear (love that show) I figured "how hard could it be?". I read the EPROM, used Google to find a dissasembler, and spent a few evenings looking through the schematics and the 28 pages of assembly code. I found the code that limits the keypad frequency input to 35.00 - 50.00 MHz and changed the limits to be 3.00 - 99.00 MHz. As Bob's cool video shows, the VA62 is designed for the 35-50 range, but will work outside that range to some extent. My Run 18 VA62 can reliably be programmed for 15.00 - 99.00 MHz. Below 15 is hit or miss. My VA62 uses a 2716 2K Byte EPROM, but the schematic shows a jumper to accomodate the 2732 4K Byte EPROM that Bob's has. The 8035 microcontroller can address two 2K Byte program memory banks. It would be useful to know if there are different firmware revisions or if they all use the same version. If you want to mod your VA62 PM me. I can supply the .HEX file if you have an EPROM burner or I can burn your EPROM if you send it to me along with a prepaid box to ship it back to you. As Bob's video shows the mod requires opening the VA62, removing the old EPROM and inserting the mod EPROM. This static sensitive electronics, so you do this at your own risk.
Hello, do you still offer the modded eprom ?, I just got a va62 off Ebay,
and your mod is just what I need.

Thanks

Bob R.
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  #69  
Old 04-09-2014, 06:18 PM
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Zenith6S321 Zenith6S321 is offline
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Yes I still have of the mod EPROMs. I will send you a PM.

Dave
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  #70  
Old 05-06-2015, 10:07 AM
aaronwhite30 aaronwhite30 is offline
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modified eeprom still available?

Hate to resurrect an old thread, but I am interested if these modified eeproms are still available for sale?
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  #71  
Old 05-06-2015, 08:03 PM
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Zenith6S321 Zenith6S321 is offline
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Aaronwhite30, yes they are still available. I just re-sent my reply to your email. Let me know if it does not make it through this time.

Dave
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  #72  
Old 05-06-2015, 08:18 PM
aaronwhite30 aaronwhite30 is offline
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eeproms

Sorry Dave, I am still not getting the emails. Are you sending them to aaronwhite30@hotmail.com? You could use my alternate email aaron30white30@gmail.com
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  #73  
Old 05-07-2015, 06:25 PM
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Zenith6S321 Zenith6S321 is offline
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Hmm, maybe a spam filter is at work? I just sent to both of the email addresses you listed. Hope it gets through.

Dave
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  #74  
Old 05-07-2015, 06:31 PM
aaronwhite30 aaronwhite30 is offline
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email trouble

CRAP! I had my receive emails from members turned off, I set it on, could you try again?
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  #75  
Old 05-07-2015, 08:07 PM
aaronwhite30 aaronwhite30 is offline
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Would it be possible to just send a Paypal invoice to my Paypal address aaronwhite30@hotmail.com?
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