Ham Radio 2000 #2/Ham Radio 2000 - Volume 2.iso/HAMV2/MODS/YAESU/ft51r-2.mod

Internet Message Format | 1997-12-21 | 6KB

From: [e-mail] (Frans Veldman)
Newsgroups: rec.radio.amateur.equipment
Subject: FT 51r mod
Date: 28 Jul 95 05:36:22 GMT
Organization: Thunderbyte anti-virus (TBAV) support HQ
Lines: 123
Message-ID: <[e-mail]>

[e-mail] (Robert Meyering) wrote:
> I just heard from a reliable source that he has seen a FT51R that has
> 800 RX. Also, I recently spoke to a YEASU tech support person and was
> told that the mod exists (as a combination HW & SW mod). Has anyone got
> information on this mod? The YEASU guy said that it provided
> capabilities similar to the FT530 mod that involved snipping the green
> wire.

Nah, it is a little different. I have been experimenting a little and
found some usefull things.

Here are the mods for the Yaesu FT-51r. Please let me know if you find
additional interesting mods.

1)  The following mod will wipe the memory contents of the radio. If you
    want to preserve the memory, make a backup of the radio into your PC
    (using RS 232 cable) first. You will need a step-up invertor (like
    the MAX 232) between the radio and the PC, and on the PC a terminal
    program that can handle all bytes (including nulls and Ctrl-Z's).
    Use 9600 bps. Hold down the F/M key while turning on, and press the
    up arrow as soon as the PC is ready to receive the data. I guess you
    understood it already. Now erase the memory, and make another
    backup. You will need this 'empty' dump later to compare the
    different bit patterns with an empty dump made after the mod, to
    patch these differences in the memory backup you want to restore.
    Otherwise the radio won't accept the original memory backup after
    you made the modification. Of course, you can also use the
    commercial software package to program the FT-51r.

2)  Remove battery and 6 screws of rear-side radio (behind the keypad).
    Also remove the battery removal clip. Loosen the other four
    rear-side screws somewhat.

3)  Carefully remove the L type plastic cover located behind the keypad.

4)  Now locate the solder pads next to the CPU:

    0          1
        0      2
    0          3
        0      4
    0          5
        0      6
    0          7

5)  Solder pad 6 is for extended TRANSMIT. Be carefull not to burn other
    components with the solder iron! If this is the only mod, you are
    ready now! (Go to 13).

6)  If you want to fiddle with the band plan of the radio, you need to
    do the following:

7)  Open solder pad 7.

8)  Temporary assemble the radio (do not fasten all screws, you will need
    to open the radio again) and insert the battery.

9)  Press and hold Vol UP/Vol DOWN & CALL keys at the same time while you
    turn the power on. The radio should respond with 'BAND #', where #
    represents the band lay-out number.

10) Press F/M for a second, and select then a different band by using
    the up and down keys (NOT THE DIAL!). I found that band 5 is the
    most interesting. Then press F/M and CALL, and it should
    automatically power off.

11) Turn on the radio, switch to extended receive (!), and check the
    VFO limits. The left VFO should run from 60 to 180 MHz, 300 to 512 MHz,
    and the right one has the same, but IN ADDITION also the range from
    700 til 999 MHz! It may be that you need to repeat the process from
    9) again but now with the right VFO active to make it work on the
    right VFO too. I found that sometimes you get different results,
    there is probably some other yet unknown factor determining what you
    get too. (Maybe the actual current VFO settings?) Repeating the
    above process and changing the band numbers again can produce
    somewhat different results.

12) Open the radio again and close solder pad 7.

13) Now securely close the radio.

14) Restore or reprogram the memories. If you want to restore a dump
    made on your PC: First make a new (empty) backup. Compare this
    backup with the one you already had, and note the few differences.
    Now patch these different bits into your original backup. Now
    you can restore it. The radio will terminate with an error because
    the checksum doesn't match, but the memory will be correctly
    programmed anyway. So who cares? For the purists: the checksum at
    the end is a simple addition of all previous bytes.

Some remarks: Although the right VFO will be able to tune into the 700
til 999 MHz frequencies, I found that the Yaesu is not able to actually
receive anything here. It seems that there are some components missing.
Although the other VFO boundaries are now wider, the sensitivity of the
radio in these 'extended' areas is poor. The same applies to the RF Power.
My RF set ceases to transmit at 500 MHz and above, but other sets may
cut off RF Power at higher or somewhat lower frequencies. I also found
the area between 60 - 100 MHz of no use, except for extremely poor
reception, it also causes interference on the other VFO. But the Mod
is worth experimenting with, and usefull near the boundaries of the
original band lay-out.

It is worth noting that with a memory backup made on a PC you can do
all kind of weird things. You can change the BCD frequenties to values
the radio wouldn't normally accept. If you want to set it to a medium wave
frequency, go ahead! Also, even in NON-extended receive mode you can
change the frequencies to out-of-band values. It works!

Anyway, please let me know what else you discover.


--

Thunderbye,
Frans Veldman

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