Modding this to the ham band is quite easy from a software standpoint. These radios are narrow band only on the receive path, as the 200 MHz band was never used for 25 KHz channels. Their are 3 filters in the radio, 1 at 44.85 MHz 1st IF and 2 at 455khz, 2nd IF.
In a normal Waris HT there is a 15KHz filter at the 1st IF followed by a 15KHz filter at the second IF and then followed by another filter. It's this last filter that is switched between narrow and wide in the VHF/UHF radios. TX deviation is a setting in programming/alignment.
In the 220 version, there 1st IF is the same, but it's got a 12KHz and then a 9 KHz filter at the second IF.
I've changed out some filters and found it works much nice on the ham bands. You need to adjust the squelch for 25khz channels after doing this. The tuner software (2.00.02) will do this, the new software will not adjust anything other than 12.5 khz. Use the old software.
220 front end 44.85MHz FL3201 MXF45 9180022M10 4-pole +-7.5khz bandwidth IF2 First filter 455KHz FL3204 CFUCJ455F 9180468V04 4-pole 12khz IF2 filter narrow band filter FL3206 CFWC455G 9180469V03 6-pole 9khz}}}
The UHF handhelds use the same arrangement, but with a wider middle filter (1st @455). In wideband they switch only the 2nd 2nd IF filter to a narrow band filter.
uhf front end 44.85MHz FL301 MXF45 9180022M11 IF2 First filter 455KHz FL302 CFUCJ455E 9180468V05 4-pole IF2 filter wide band filter FL303 CFWC455E 9180469V05 6-pole IF2 filter narrow band filter FL304 CFWC455G 9180469V03 6-pole
The 1st IF is under the shield, and very hard to remove. I've not messed with it, as it appears to be the same part in the UHF
Based on the following codes for muratta filters
Muratta filters E is +- 7.5 (15) F is +-6 (12) G is +- 4.5 (9)
The 220 Filters are 12 and 9 Khz wide at the 2nd IF. Switching them to the E filters of the UHF HT1250 is rather easy, as they are just on the underside of the board, not under a shield. An under board heater with a hot air station makes this rather easy.
Ive found an under-board board pre-heater is mandatory to work with this and 630f at 7 l/m of airflow will prevent hurting the board/parts/
I've found the sensitivity to be a bit better and no squelch clipping on 3.2kc tone at 7khz of deviation (Most ham rigs on 220 have WIDE deviation!).
The easiest way to mod this is using the 255 channel srecord.
Code Plug Map
This is based on the Srecord file loaded as binary
0x282 - 0x2D7 - group, needs to be 5A checksum, adjust 0x2D7 to make it. 0x285-0x28E - Serial number 0x291-0x2A0 - Model number, Blank should be spaces 0x20 0x2AC Channel steps *0x01 - 12.5, 20 and 25 KHz *0x05 - 12.5 only 0x2AF Lower Frequency Limit 0x2B1 Upper frequency limit Desired limit - Base freq (200mhz models the base freq is 103mhz) times 1000 then divided by 5. this gives you the new value in dec, you have to change it to hex 216 MHz is 5848 225 MHZ is 5F50
0x2AC Channel steps 0x01 - 12.5, 20 and 25 KHz 0x05 - 12.5 only
0x2D8 to 0x2E9 - group, needs to be 5A checksum, adjust 0x2E9 to make it. 0x2E2 - Number of personalities is at in hex. *128 - 0x80 *160 - 0xA0 *255 - 0xFF
The 8 bit checksum must be 0x5A for this bit of code. Byte 0x2E9 is the checksum fix bit. Find the difference after editing between the checksum and 0x5A, then add or subtract this from the value in offset 0x2E9.
File:HT1250LS 217-222 split to 216-225 split.s19 This has problems