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Yaesu FT-817 CW Filters

As i know next to nothing about CW filters i have a couple of questions.

Which is the best CW filter for the FT-817 … bandwidth, cost and make?

Also where is the filtering done … AF, IF or elsewhere? Hope that doesnt sound too stupid but before i buy a filter i would like to know what i am buying. Sean M0GIA

In reply to M0GIA:

B/W is a difficult question to answer but the choice is 300Hz or 500Hz. All of the filters on sale are Collins mechanical filters with different sticky labels applied by the vendor! Filtering takes place at the second IF, 455kHz

I have a 300Hz B/W Inrad which I obtained 2nd hand.


In reply to M0GIA:
As Andy says B/W is a matter of personal preference.
I have a Yaesu (badged ;o) ) 500Hz filter in my FT-817. Also bought used - an eBay BIN from an amateur in the USA who trades in used kit.
The weaker the received signal the greater chance you have of losing it completely in a narrow bandwidth.
73 Graham G4FUJ

Sean, whatever filter you get, you are about to find your CW get a whole lot easier! I think mine are 500, but I’m not sure. 300 are better for concentrating on the intended signal and blocking out other disturbances, but you can ‘miss’ weaker signals as Graham mentions. I have filters for both the 817 and the 897, and they are very easy to fit (even for me).

The 817 filter was one of the best SOTA accessories I ever bought, along with the Palm Paddle. How long now before your debut CW activation? I’m looking forward to it, cannot fault your determination.

Have you started calling the spotted CW activators yet?


In reply to M1EYP:

Recently compared the INRAD 300Hz and the original YAESU 300Hz Filter in the same rig (FT-857). The Inrad was less noisy.

FT-857 was used since it can hold 2 CW filters. Similar filters are used in the FT-817.

Price differenc INRAD/YAESU is minor.



In reply to DF9TS:

See http://www.sotawatch.org/reflector.php?topic=2893 and last link in particular http://www.rofike.hu/Filters/filters%20002.jpg


In reply to M0GIA:

I am using a 300 Hz FIlter in the FT 817. Works good. You’ll find some examples on youtube, there you can see / hear the difference between the filters and using no filter. Here is a 500 Hz filter-movie:

73, Mario

In reply to M1EYP:
I think i will go for a 500hz filter myself and for what i have in mind, As i enjoy the dx side of activating i will be wanting to hear the weaker signals.

I do not know when i will be doing my first solo debut CW activation, 20ft of speaker wire hung over the mirror in the living room is where i am at the moment so its a struggle to hear anything from lots of QRM so no chasing done just yet. Shack relocation due shortly which means i can get a feeder to the radio!

I took your advice Tom and started to listen with my 20ft of wire, After what must be hours of listening to ARRL 5wpm and now FISTS 12wpm files i seemed to have had a breakthrough in recieving. I was tuning around top band lastnight when i heard a big signal over the top of the QRM, I hope it was not a fluke but after a few CQ calls from this big signal GM0UDL appeared on a sheet of paper in front me!

Some find CW easy but for me its been a struggle which has caused frustration in the past resulting in a self convincing belief of not being able grasp it. I noticed a few nights back watching some of Goathikers videos on youtube where he has the call signs up i could clearly read the characters from his radio. I need to go over some operating procedures now, Then see what 5w can do. Sean M0GIA

In reply to M0GIA:


bear in mind that a 500Hz is much wider than 500Hz. -3dB are abrely audible.
Experienced CW ops can focus on single sigs in wide filters. For you it may be an additional burden.

300Hz limits the spectrum but is perfectly ok even for off frequency stations.

I am using wide filters for CW at home but use 300Hz in SOTA “small pile-up” situations. Still 5 or so ops fit in the socalled “300Hz” filter.

Your choice.


In reply to DF9TS:
Thanks Gerd and Mario, I will checkout the youtube video’s later tonight so i can have a listen myself. A few weeks yet until my birthday so time to make an informed decision … dont you just love birthdays? Sean M0GIA

In reply to M0GIA:
Your taste!
I have a 500MHz “official” one, which I’m happy with, but I’d probably get a narrower one these days. Certainly, the 500Hz is an awful lot better than nothing.

In reply to M0GIA:
I bought the the narrow 300HZ filter on the W4RT board, personally i feel I made a mistake and its too narrow although it might be a matter of getting used to it. I would certainly try and listen to the two before you buy. I also have a problem with my OBF W4RT in that it has images of the main signal on either side of the 300HZ filter, well down but a pest on 2m when looking for weak beacons etc. Am in discussion with W4RT who are trying to sort it out for me :frowning:

In reply to GM4GUF:
So far I have only watched the youtube videos of the 300hz and 500hz filters, After watching those clips all I know is my RX on CW is as wide as a barn door! Which ever i decide on I am sure it will be an improvement. Sean M0GIA

In reply to M0GIA:
I’s not just width. You’ll get ringing on a very narrow filter, unless you go for a very upmarket rig - that is, the background noise will just confuse things.

But I agree with you: the 817 on CW, on 80m or 40m on a Saturday afternoon, needs a filter. I gave up in the shack this afternoon - wall to wall “TEST”…

In reply to M0DEV:

I gave up in the shack this afternoon -
wall to wall “TEST”…

I listen to 30m CW more and more on weekends - no TESTs!! :o))
And, usually, a few EU SOTAs throughout the day.

73 Graham G4FUJ

The target by the end of the day today, is to have a 30m dipole for my SOTA activating. My only ever SOTA 10MHz work before has been on the joint activations with LA1KHA, LA1ENA & LA1TPA, borrowing Kjell’s antenna. The band hasn’t had nearly enough attention from me. But hopefully, this year…


In reply to M0GIA:

I don’t know why I’m following this thread, I haven’t got a hope of learning CW any time soon, though I very much aspire to when my brain is less full of economics, policy and hydrology! I thinks its the “radioness” I’m liking.

Have a look here:

This chap rolled his own 500hz filter for the 817. No specs, but looks dead simple. His blog portrays him as helpful sort of ham. There’s a link on there to a youtube video of the filter in action.