Narrow Filters - Ringing ?

[Froggythefrog]

Just a quick question.

When on CW mode using narrow filters, 500/250 I get this ringing all the
time, I'm guessing this is caused by the background noise on the bands
coming in via the narrow filters.

I operate mainly on 160/80/40/30m CW thus I am wondering if it is
possible to do something to the rig to get rid of the ringing effect ?

The rig I use for CW is a Tentec Omni VI with the roofing filter
modifications.

I also have an FT1000MP which suffers exactly the same problem, however
I don't like using it on CW as it has terrible key click problems, as
per all the Yaesu range of radios.

So, is this problem cureable or is there a radio on the market now that
doesn't suffer from this problem ?

Thanks for any help.

[Dale Parfitt]

"Froggythefrog" > wrote in message
...
> Just a quick question.
>
> When on CW mode using narrow filters, 500/250 I get this ringing all the
> time, I'm guessing this is caused by the background noise on the bands
> coming in via the narrow filters.
>
> I operate mainly on 160/80/40/30m CW thus I am wondering if it is possible
> to do something to the rig to get rid of the ringing effect ?
>
> The rig I use for CW is a Tentec Omni VI with the roofing filter
> modifications.
>
> I also have an FT1000MP which suffers exactly the same problem, however I
> don't like using it on CW as it has terrible key click problems, as per
> all the Yaesu range of radios.
>
> So, is this problem cureable or is there a radio on the market now that
> doesn't suffer from this problem ?
>
> Thanks for any help.
>

I recently had the opportunity to hear both a 250Hz (from memory) stock
FT-1000 filter and a homebrew same bandwidth filter whose group delay
response had been optimized- the difference was very obvious. I am not aware
of any amateur filter manufacturers that at least claim to be paying
attention to this parameter. See W7ZOI's text Experimental Methods in RF
Design for a treatment.

Dale W4OP

[Froggythefrog]

Dale Parfitt wrote:
> "Froggythefrog" > wrote in message
> ...
>
>>Just a quick question.
>>
>>When on CW mode using narrow filters, 500/250 I get this ringing all the
>>time, I'm guessing this is caused by the background noise on the bands
>>coming in via the narrow filters.
>>
>>I operate mainly on 160/80/40/30m CW thus I am wondering if it is possible
>>to do something to the rig to get rid of the ringing effect ?
>>
>>The rig I use for CW is a Tentec Omni VI with the roofing filter
>>modifications.
>>
>>I also have an FT1000MP which suffers exactly the same problem, however I
>>don't like using it on CW as it has terrible key click problems, as per
>>all the Yaesu range of radios.
>>
>>So, is this problem cureable or is there a radio on the market now that
>>doesn't suffer from this problem ?
>>
>>Thanks for any help.
>>
>
>
> I recently had the opportunity to hear both a 250Hz (from memory) stock
> FT-1000 filter and a homebrew same bandwidth filter whose group delay
> response had been optimized- the difference was very obvious. I am not aware
> of any amateur filter manufacturers that at least claim to be paying
> attention to this parameter. See W7ZOI's text Experimental Methods in RF
> Design for a treatment.
>
> Dale W4OP
>
>

Hi Dale,

Thanks for this, I'll search the internet for the text.

Cheers !