First came the FT-220, a 10W 2m multi-mode transceiver also sold as the Sommerkamp in Europe. It covers 144-146 MHz in four 500 kHz ranges, which is good for Europe but not for the USA. There was also a 6m set called the FT-690.
In contrast, the FT-221 is much more complicated, even though the specs are not that dissimilar (although coverage is 144-148 MHz in eight bands).
The FT-221 uses an analogue PLL, and plug-in modules like the FT-101 and others. The design is by no means modular though -- the relay that switches the repeater crystals is on the tone burst board, and the voltage source that tunes the varicaps in the front end is on the marker unit, for example.
There are web sites (2015-08-18: Wikipedia) who will tell you that the FT-221R is the repeater-capable version of the FT-221 this is not true. Both offer repeater split frequencies, but the FT-221R offers options other than 600kHz split (FT-221: S8 is RPT ON/OFF, S9 is RPT NOR/REV. FT-221R: S8 is RPT 600/OFF/AUX, S9 is RPT NOR/REV). There are four crystal positions for repeater operation, the FT-221 supports repeaters on four of the eight 500 kHz segments, while the FT-221R supports standard and non-standard repeater shifts on two segments only -- if wired according to the schematics I've seen, that is. In Europe and South Africa, repeaters are in the 145-146 MHz segment so the switches would need to be wired accordingly.
The FT-221RD has a digital display. I suppose this is just an internal YC-221.
The FT-225 is an upgrade of the FT-221, many FT-221 tips & tricks also apply to the FT-225 and vice versa.
The FT-221R Yahoo group has a file that describes how YU1PKW and YU1EU modified the FT-221 front end to reduce the noise figure by 2-3 dB. This looks like a worthwhile mod.
|
|
Back | (This page last modified 2017-09-15) |