I received the following mods for 24AT out-of-band from a very reliable
source (although they don't specify RX only or RX/TX), for 75-195 MHz,
200-490 MHz, and 740-960 MHz. Rumor has it (unconfirmed) that the unit
even switches to AM in the air band!
-
Remove diode D8 [see figure below]
-
Attach diode D7 [I believe this is already equipped]
-
Attach diode D12
-
Remove diode D13
-
Simultaneously hold "LIGHT", "B", and "#" keys and turn the
power on. Release all keys after the display goes out (checks
all LCD segments). [This is supposed to enable the
out-of-band frequencies above]
-
Simultaneously hold "LIGHT" and "2" keys and turn the
power on. This enables the 10 MHz frequency digit entry.
-
Simultaneously hold "LIGHT" and "3" keys and turn the
power on. This enables the 100 MHz frequency digit entry.
__________________
| |
| |
| |
| CPU |
| |
| |
| |
|________________|
o o o D7 lower left pin is
[D7] [D8] anode of one diode,
o o o lower right is cathode
of the other. Top pin
o o is common
[D12]
o D12 upper pins are cath-
odes of diodes, lower
is common anode.
__I_ __I_ See text
| | | |
D13 |__| | | D?
|/| | |
| | | |
|__| |__|
I I
WARNING: I have NOT tried the hardware mods and cannot vouch for them, so
proceed at your own risk!
I am told that the newer 24AT's (believed not to have made it to the US
yet) will have the hardware mods in place, so only steps 5-7 will be
necessary. So, try this first. Steps 5-7 don't seem to have any effect
on a 24AT without the correct hardware mods. BTW, this has been attempted
on 2 units with serial numbers around 1000 and mid-1100's, neither of which
worked. :-( Like I said, the ones with the mods aren't here yet.
There are 5 screws to remove the case (5th is on the strap hook). Keep
the top panel controls with the front of the radio, and be VERY careful
pulling the back off because there are fine ribbon cables connecting the
front & back. I don't think they'll take much flexing.
Additionally, diodes D7, D8, and D12 are surface mount components. They
contain 2 diodes connected to 3 pins. Diodes D7 and D12 are different
configurations. I believe D8 and D12 are different, so I wouldn't put the
removed D8 in the spot for D12. Since they are surface mount, removal of
D8 may not be all that difficult for those with steady hands and a fine
low power soldering iron, but adding D12 would be a bear. I know of no
reason that small discrete diodes couldn't be used in for D12. D13 is a
small but standard axial diode, and can be easily cut.
It is for this reason I have not attempted the hardware mods. Now, if the
referenced posting is correct, and only D13 needs to be cut... I'm
guessing, but it could be that the rest of the diode changes are for the
10 MHz & 100 MHz digit entry (which I'd like but could live without) or
out-of-band TX, or the like.
Transmit range doesn't appear to be affected unfortunately. I was at
least hoping for 420-450 coverage. BTW, I tried each amateur band from
6m to 23cm. The PLL doesn't lock up at either end. Another negative
is the frequency step on 220 doesn't allow one to hit each possible
repeater slot.
|
