Originally Posted by TubeType (Post 3034945)

I have been asked whether there are any differences between the Sencor VA62 and the VA62A. I have always thought they were functionally identical. Can anyone shed any light on this subject?
Thanks,

Originally Posted by cwmoser (Post 3035052)

I posed the same question some time ago and the answer I got was that the only difference between the VA-62 and the VA-62A was that the "A" version extended the UHF channel range. Today that is so little an issue that I would go after the best condition/price and not consider if its "A" or not.

Carl

Originally Posted by Phil Nelson (Post 3029884)

On request, I posted the VA62A files temporarily on my website.

Originally Posted by ChrisW6ATV (Post 3057956)

Thank you for posting the VA62A information, Phil. I appreciate your efforts.

Originally Posted by Zenith6S321 (Post 3029496)

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.