I’m about to take the plunge and order a CW filter for my FT817.
I’m a little unsure about the width of filter will best suit my needs. I didn’t do much CW when I bought the FT817 way back in April 2001 (It’s older than SOTA!), but now it’s the mode I nearly always use.
I seem to have pretty good hearing still (33yr). I’m very tempted by the 300Hz filter but I have survived with RockMites and the like for the past year and have managed OK. I like my KD1JV MTR which utilises a 4 crystal IF ladder filter with a quoted width of 500Hz.
I’ve got one of each in my 817’s. The 300Hz one is in the 817ND which is the main rig at present and the one I’ve used most. The 500Hz one only arrived a few weeks back. Too much of a bargain to resist at £60! Which one? 500Hz would be better for some digital modes that wont fit in a 300Hz filter. But I’d leave the advice as which is best for copying Morse by ear to people who have some serious miles on the clock Colin. The skilful ones don’t need a filter but I’m not one of them.
Doesn’t matter. I’m very serious. The front-end is so wide open, you won’t be able to copy through any QRM anywhere on the band, anyway. You need a receiver with a better front-end before you can worry about the back end
I’m about to take the plunge and order a CW filter for my FT817.
300Hz or 500Hz?
I got mine off Ebay and found a 300Hz one first. I found it too narrow, not so much for actually listening as for tuning, the passband is so narrow it’s actually difficult to find the signal. I later found a 500Hz one, again on Ebay, and find it not much worse when listening but much easier to tune with. I sold the 300Hz one on to a local club member.
I bought a Collins 300Hz one for my FT817 from W4RT for $119 +P&P (No VAT) and am very happy with it . I use it often when /p qrp on the summits.
On the other hand I have a Yaesu 500Hz one fitted in my FT857 which is used for CW on the summits and Data use in the occassional contest if away from home.
I bought INRAD filter #712 300Hz 2.5:1 shape factor ($125) for my FT857 and I am very pleased with it. I think the INRAD or W4RT filters are better than the Yaesu ones. I find the FT857 (I think FT817 RX is very similar) fitted with the 300Hz CW filter works very well on 40M CW where there are often stations operating only 500Hz apart. I haven’t noticed any tuning difficulties when using a 300Hz filter.
I think the INRAD or W4RT filters are better than the Yaesu ones.
They are definitely better, both are made by Collins but the INRAD ones are a better spec (and shape). I have an INRAD CW filter in my FT-920 and like it much better than the Yaesu one in my FT-817ND
I was thinking of the W4RT filters, they seem to work out a little cheaper than ones from the UK (provided the guys at Mount Pleasant are in a good mood!).
I’m still a little unsure about which filter to purchase! I was nearly convinced about the 500Hz one, but now I’m not too sure. I expect I will use my MTR for 40m CW most of the time I find it’s performance mind blowing, it’s so selective
I want to use the FT817 for the other bands.
Fred - given the choice of a better rig, I’d probably go for something like the KX3, but I’m a little short of the couple of thousand dollars at the moment! I can’t justify spending so much cash at the moment, even though I have official permission (XYL!).
I guess I ought to get building the K1 that’s sat here in kit form - It’s a builder for hire job, but I have been granted 2 weeks to ‘play’ with it after completion.
In reply to M0CGH:
I agree with Colin G8TMV - I looked at INRAD vs W4RT and concluded that they had a better shape factor and spec. The INRAD filters are a little bit more expensive but I feel the slightly higher cost is justified.
I guess I ought to get building the K1 that’s sat here in kit form -
It’s a builder for hire job, but I have been granted 2 weeks to ‘play’
with it after completion.
Does the owner realise it’s going to be delivered complete with “summit mud”
HI Colin
If it were me with a single IF filter in the FT-817 I would choose the 300 Hz filter unless I could purchase a cheap second hand 500 Hz filter if one came up for the price Andy MM0FMF paid for his second hand one! If you could fit selectable filters in two IFs then I would choose a 500Hz in one IF and a 300 Hz in t’other, but as this is not possible in the FT857/817 range and the rx is not that tight anyway I would choose the 300 Hz one every time.
On a summit when the hordes are calling you on CW due to your popularity you don’t need to do any tuning round so the tighter the rx is the better.
I’ve compared both the 500hz and the 300hz filters in my FT-817. The 500hz was just too broad. I believe the 300hz filter performs more like a 500hz filter (i.e., they’re actually broader than their specified BW).
I find the FT-817 receiver performs quite well on cw when equipped with the 300hz filter.
I bought a Collins 300Hz one for my FT817 from W4RT… I have a Yaesu 500Hz one fitted in my FT857.
SNAP! … and I much prefer the 300Hz filter.
In reply to N1EU:
I find the FT-817 receiver performs quite well on cw when equipped with the 300hz filter.
For twenty years I used the filter in my head before getting a 500Hz one for my TS-130V and I found it to be a revelation. I don’t find that much difference between the Kenwood 500Hz filter and the W4RT 300Hz one which is probably similar to the comparison you have made. It seems to me that the Yaesu 500Hz filter may just have too wide a skirt and that is why I am not particularly enamoured.
I have read that there is some leakage of signal around the filters in the FT 8*7 series leading to a degradation of the skirt selectivity. This problem might be cleaned up somewhat by making an audio filter to go in-line with the headphones, a tunable notch would be a useful feature to add!
I’m used both 500 and 300 Hz filters before (not in FT-817), and have 500 Hz filter in FT-817. 300 Hz filter is good for VERY crowded band, such as during CQ WW contest etc. 500 Hz is preferable for ‘ordinary’ QSO (I’m even usually used 1 kHz filter here) and small pile-ups, since not all the callers call you exact at your FREQ. Moreover, I’m won 2 Fiel Day contest with FT-817 & 500 Hz filter - the last is still comfortable for ‘low level’ contests. So, I’m not sure, that I need 300 Hz filter in FT-817 at all, except the case if I’m amongst a pile of ‘big guns’.
I guess I ought to get building the K1 that’s sat here in kit form -
It’s a builder for hire job, but I have been granted 2 weeks to
‘play’
with it after completion.
Does the owner realise it’s going to be delivered complete with
“summit mud”
Colin G8TMV
The K1 is just about finished now, I just need to install the ATU.
