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eHam Forums => Elmers => Topic started by: LENNNIE on September 26, 2007, 03:32:18 AM



Title: Filters for the ts-570
Post by: LENNNIE on September 26, 2007, 03:32:18 AM
I recently bought a ts-570 radio and once I got it home and started listening to it I decided that maybe it would be a good idea to get a couple filters for it, one for ssb and one for cw.  When I looked into it further I found that there's only one spot.  I like doing both cw and ssb.  Can you guys who have owned 570's tell me which is best to get a filter for or if there's some way to put a second filter in the 570?  Thanks.  Len. KD8CWP


Title: Filters for the ts-570
Post by: LA4RT on September 26, 2007, 03:56:02 AM
It comes with an SSB filter. You can either use the extra filter spot for a CW filter, or for another, narrower, SSB filter. The narrower SSB filter is useful for DX work . (I'm told - all my DX work is CW).

73
Jon


Title: Filters for the ts-570
Post by: WA3SKN on September 26, 2007, 04:11:56 AM
For SSB, consider the 2.1 Khz filter. 1.8 Khz is too narrow.
For CW, most prefer the 500 Hz filters, the 200-250 Hz filters are too narrow for most operators.
INRAD has filters for just about any radio that was ever made, check them out!

-Mike.


Title: Filters for the ts-570
Post by: VE3XDB on September 26, 2007, 05:40:32 AM
I am primarily a CW operator, so was most interested in improving the filter blow by and adjacent signal interference that I encountered from time to time.  Decided on the Inrad 400 Hz filter, which does the job well.  Here is a link to the Inrad web page, with information about this particular filter:

http://tinyurl.com/2g7guq

Best regards,

Doug VE3XDB



Title: Filters for the ts-570
Post by: KB9CRY on September 26, 2007, 05:56:08 AM
500 Hz CW is what you want.


Title: Filters for the ts-570
Post by: WT0A on September 26, 2007, 06:33:26 AM
Len If you operate CW get the 500hz filter for sure. On SSB you can narrow it up using the DSP Slope.
Glen


Title: Filters for the ts-570
Post by: W5ONV on September 26, 2007, 03:45:42 PM
 I bought and installed the Kenwood 1.8 khz SSB filter.I sold it about 6 months later. I could hardly tell and difference at all with the filter.It would make the audio sound bad and did not really seperate the close by stations very well.Maybe an Inrad filter would have done better or maybe not,I have never tried one. The 570 is just fine the way it is with no extra filter installed for SSB in my opinion.If you operate CW alot I would invest in a good CW filter.


Title: Filters for the ts-570
Post by: WA9SVD on September 26, 2007, 09:05:17 PM
With the DSP, you can get the stock radio down to 50 Hz bandwidth in CW mode, so you may or may not notice a big difference if you were to get a CW filter.
    The narrow SSB filter (1.8 kHz) DOES make a big difference in cutting out noise and adjacent interference, and (obviously) it DOES alter the sound, due to narrower bandwidth.  (It's the nature of the beast; you will not get broadcast quality sound.)  But it DOES make a difference.  It is unfortunate, (in a way) that you can't add more than one filter.
    Inrad still makes filters for the '570; Kenwood has stopped production, so that brand filter may become difficult to find.

    The only SSB filter available from Kenwood for the '570 is a 1.8 kHz filter, there is no other SSB filter available from Kenwood.  Check page 38 of the owner's manual for the various filter/bandwidth combinations possible with the optional filters.  


Title: Filters for the ts-570
Post by: KE3WD on September 27, 2007, 10:24:23 AM
Doesn't the 570 have AF DSP?  

Specifications/Manual confirm that it does.  

DSP at the AF level will do little to solve adjacent channel overloading, which is what a good IF stage filter or IF level DSP can do for you.  

Problem with AF DSP is that the receiver frontend is often already overloaded before the signal gets to the DSP...

Since this rig does indeed feature IF Shift, I'd go for the CW filter and use the IF Shift when sideband interference might be the issue.  

When there is s strong CW signal right next to the weak one (and often not so weak one) that you are trying to copy, the pumping in and out can be so severe sans a good IF stage filter that it makes copying the station impossible at times.  

Of course, all depends upon your preferred operating modes, too, those who don't do CW have already answered the which filter for me question.  


KE3WD


Title: Filters for the ts-570
Post by: WA9SVD on September 27, 2007, 02:22:45 PM
Point taken.  If you DO operate predominately CW, the the CW IF filter will do better than the AF DSP.  But unless you are accustomed to using a really narrow CW filter, the 270 Hz filter may take a bit getting used to, and the 500 Hz filter might be a better choice.  It's too bad you can't add more than one filter.


Title: Filters for the ts-570
Post by: LENNNIE on September 27, 2007, 02:44:04 PM
Thanks all for your input.  I'm sure that a certain portion of my problem is caused by just not knowing which controls to turn on or off to get the desired results.  Eventually I'll learn and you have been a big help.  Len.