Is a new ft-891 not the price of a used ft-857D?
Then get the 891 if HF is your primary thing
John VE3IPS
1 Like
Yep, they’re too stubborn to improve!
The DSP of FT-857 is really not bad at implementing a narrow CW pass. But, unfortunately, this narrow-band filter is outside the AGC loop. Accordingly, if there is an undesirable, powerful signal in the IF filter band, the AGC will also react to it. Accordingly, a weak DX signal in the DSP band of the filter will be attenuated to the beat with signal of interference. That is why there is no special gain from this function in real PileUp.
73
1 Like
Yes, this is an inherent problem with audio DSP. Some people recommend switching off the AGC, turning the AF gain high and using the RF gain as a volume control but then a headphone user needs a diode limiter across the phones to protect his ears if a powerful signal appears in the passband!
1 Like
That’s why a crystal filter is necessary for serious CW work if using the FT-857.
1 Like
IIRC, in his review Peter Hart said that you would be unlikely to get the full benefit of putting a narrow filter in the FT857 because the layout would permit some signal to bleed around the filter. Still, it isn’t bad for a jack of all trades, master of none type of rig!
Now operating as 9H3DS where the sun shines and temp 25C. But not a good forecast tomorrow.
My 857 has a 500 hz mech filter. I agree it is very desirable for cw. The dsp filter is ok on a noisy band but fails miserably in a pilup. As discussed, the agc issue. You are correct Phil that high tx power does increase to number of callers. All that said I can usually pick one or more calls out of the pilup and maintain a casual 1qso per minute.
I believe the problem of resolving a narrow pilup is cross mod. due to intermodulation. So a higher close in dynamic range should help, as home experience suggest.
I think a field test on a local easy access summit is called for prior to sending my letter up the chimney to FC.
Once again thanks for the ideas. I will advise on any develpments.
Regards
G0EVV… 9H3DS
I’ve only used my 891 for ssb, and found it has a much better receiver than the 817. Also, regardless of the S-point debate, I find I get more contacts with 100W than with 5. However, the KX2 seems a lovely radio as does the new 10W Icom due in the Spring & those plus a 40W amp would probably do very well too, particularly on CW.
Martin
Well said sir! I always say the same thing ¨Before buy filters or looking for DSPs, improve your listening capabilities¨. Nothing better that the natural filters and DSP located between ears.
Playing with MorseRunner is the best investment.
73 de JP3PPL
2 Likes
I’ve used an 891 for over a year, hauling it up to peaks and having a lot of fun. I’ve since downsized (and dropped some weight) by going to a KX2. I still use the 891, for instance, the last SSB contenst I was on a peak and had a blast. 100w helps break pileups you can’t get into with 10w. I’ve used it for just a little CW. I do like all the filtering and DNR capabilities. I’ve had a lot of FUN with it.
Fun is what this is all about, right?
1 Like
