[Boatanchors] QEX Dec 1988 Article

[Bill Cromwell]

Hi,

I once used a passive L-C audio filter built around those. I may still 
have it and may still have some more 88 mH toroids ( I once hade five of 
them). They did a nice job at the time but other filtering schemes run 
circles around them. They do what they always did and are good for 
nostalgia:) For on-air use I will take the DSP machines:)

I could be talked into parting with my 88 mH toroids assuming I can find 
them:)

73,

Bill  KU8H

bark less - wag more

On 7/12/20 12:09 PM, w5jo at brightok.net wrote:
> 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
>>
> 
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