[Boatanchors] QEX Dec 1988 Article

[w5jo at brightok.net]

Someone refresh my memory abut those coils Grant mentioned.  I have 10 coils 
that, as I recall, are that type but am short on memory.

These are toroid and a lot of wire on them, indicating a large inductance. 
There are 5 with Red wire and 5 with Green wire.  If I recall they are 88 
and 44 mH but I can't be sure.

Does this ring a bell with anyone?  I inherited them in an estate from a 
local ham who was prone to save things like that and I did not look at them 
until just after reading message from Grant and Scott.

Should they be of use, postage will get them.

Jim
W5JO


-----Original Message----- 


While not Wetherhold’s filters, there is a Crud-o-ject filter in a 1972 QST 
which looks to have a similar bandwidth.

I built the later SSB Crud-o-ject which I wish I still had, but parted with 
a long time ago.  I had it built into a Heath SB-600 speaker.  These were 
both basically “noise and crud” filters, but the original version for CW is 
relatively narrow.  Someone also produced commercial versions of these.  It’s 
too bad that 88/44/22 mH coils have become so seemingly scarce.

Grant NQ5T

> On Jul 12, 2020, at 11:12 AM, <whitebear1122 at comcast.net> 
> <whitebear1122 at comcast.net> wrote:
>
> Hi, I'm trying to get my hands on an article from December 1988 QEX.  It 
> is
> not available through the ARRL's magazine Archives.  The article is by 
> W3NQN
> titled "CW and SSB Audio Filters Using 88 mH Inductors.
>
>
>
> I'm looking to build LC SSB and CW audio filters for my homebrew HBR-13
> receiver.  I'd like to narrow up the CW bandpass to something like 
> 800-1000
> Hz.
>
> Thanks.  73, Scott WA9WFA
>