Batboard

I'm looking to program a low band 29.7 - 37 MHz Vertex VX4000L onto 10m

The lower band limit is currently 29.7 MHz.

Anybody done the mod?

I've read up about the 440MHz VX4000 mod but when I try and "find" the 29.7 MHz band limits using a hex editor I'm having no luck...although the procedure works OK on 440MHz. I've tried a number of combinations of "297000....." but there is no hex match.

Any ideas?

29700000?

Sadly No.

I've tried every combination of 297 to 297000000 as well as 37 to 3700000000 but no hex match

I checked out the 450 MHz "codeplug" and did get a hex match using 450000000 so the low band radio must be different.

The default limits are definitely 29.7 and 37 MHz

If I remember right, the other band limits should be nearby the 450 frequency...

As I understand it, the hex editing involves editing default.c49 "codeplugs" which are frequency specific - so the 29.7MHz codeplug is just for Low Band and contains no 450 MHz data.

I did look for Low Band band limits in the same location as the 450 MHz band limits but there was nothing that seemed to make sense.

I'm hoping that I can find somebody who has previously successfully modded a 10m or 6m VX4000.

Well I've successfully programmed my low band VX4000.

The issue was that the decimal to hex converter did not include a "zero" at the start of the 29.7 Hex value - it should have been 01C52FA0 rather than just 1C52FA0. I added the zero and it all worked. You simply have to remember that the Vertex software uses 8 hex digits for the band limits. If the hex converter only gives 7 digits, then add a zero to the start.

Only problem now if that the VX4000 works great on 29.660 and above but is completely deaf below 29.660MHz - sensitivity seems to fall off a cliff rather than a gentle decline. I guess the band pass filters need adjusting.

So has anybody ever aligned a VX4000 or VX5500 or VX6000?

Yeah...I found my old text file notes that made mention of the leading zero in the hex frequency.

Did you ever align your VX4000?

g8tzl2004 wrote:Did you ever align your VX4000?

I had a hi-band VHF one for a bit I had a friend align; he had no issue with it as I recall.