PA3CLQ's Leuke Linken Nr. 473


Ferrit location

This is a little OT, but when putting ferrites on wall warts, do you put them right where they plug into the 110, or at the end where it plugs into the apparatus?

I get some white noise when B1MM starts up and would like to get rid of it.

Thanks and 73 Tom W7WHY

    Usually near the radio/device.

Mike, NA6MB

    I'd place them as close to the wart as possible ... the cable to the device will act as an antenna if it is choked at the device end.

Not sure what a wall wart has to do with N1MM starting up, but at the wart should be best.
73, Fred ["Skip"] K6DGW   

    Playing with chokes is a good thing.

From my personal experience with real world measurements.Add them at the antenna to keep RF off the feeline

  • Add them at the radio to stop your feedline from being an antenna. (if you want to test this, go to 20M and see if you can copy FT8 without an antenna actually connected - you should not be able to. Your noise floor should be quiet. If it isn't, then you have more antenna then you planned to)
  • On all wall warts, but have a listen with an AM Radio. BTW, Garmin USB wall warts are the worst!

The quieter you are, the more you can hear.

Chokes are required for not only receiving, but transmitting.

Lastly, read this YCCC Choke document.

If the link doesn't make it, google yccc chokes and read the PDF document.

I now buy chokes multiples of 25 or 50.

It is seriously worth the investment.

Mike va3mw

    Better yet, don't use noisy wall warts, replace the noisy ones, which are switch-mode power supplies, with old-fashioned linear wall warts that you buy at flea markets and second hand stores, where they're typically a buck apiece.

Lots of details on this in

and with pictures in

BTW -- if your noise increases when N1MM starts, I'd suspect the computer video card and/or the monitor.

I had this problem in Chicago with Thinkpads when most of my antennas were pretty close to the shack. 
Choking the power cables for both computer and monitor (assuming external monitor) and the video cable CAN help, but not if the noise is radiated by the video display's internal wiring.

That's what was happening with my Thinkpads.

 I've seen noise from video monitors with setups for 7QP, CQP, and FD with close antennas.

And I've seen it from Thinkpads on 2M when set up for a grid expedition -- in that case, we had to use a different laptop.
73, Jim K9YC
    OK, the video card might be the culprit, I had some issues with an old Dell laptop supplied by my employer a number of years ago.

Some programs [e.g. Lotus Notes] were noisy, others [MS Excel] weren't.

I misread your post that the noise occurred when you were starting N1MM as opposed to when it was running.

Good luck with the quest.
73, Fred ["Skip"] K6DGW


Calm down... #Admin

Avoid making or responding to inappropriate posts.

Everyone involved gets moderated, which just makes more work for moderators. 
No need to respond to this post either.
73, Drew AF2Z SKCC Group


Hearing impaired 700hz

I am trying to find an outboard audio filter(passive or active) that isn't fixed at the usual 700hz sidetone freq.

So many have been made I feel I could research for ever.

I have found 500hz and 850hz usable for me.

My hearing now has notches not to mention very weak.

I believe many high end filters like the timewave 599zx and mfj784b are tune-able.

My rig is an Icom 751a with stock filters and soon to have the fl52a or inrad 116 narrow filter in the second IF.

Tks Ray 7713

    If you can still find one, I used an Autek Labs QF-1 audio filter.

It has tunable and variable width peak and notch that can be used together even, very effective.

CW is Real Radio 73, John...K8JD
    Hello this one perhaps?


    That Calf filter is not immediatly tunable, it has preset steps and no variable bandwidth, I don't think it is very flexable.
CW is Real Radio 73, John...K8JD
    I read:
For assembled units choose either:
Fixed - The filter resistors and capacitors are soldered in place  or
Experimental - IC sockets are soldered in place for easy changing of filter types and values.

RC values must be inserted after shipping
So it can modified for 500Hz or 850Hz maybe with an additional switch for the desired freq i think.
Maybe we can ask KC9ON about this question.
It has 5 switch selectable, offering various bandwidths from 700-100Hz on a 700Hz center frequency
73, Jan PA3CLQ
    Are you sure you can't adjust the sidetone pitch of your rig to something other than 700 Hz?

There may be an internal adjustment.
Otherwise, it seems to me from what you are proposing, that you will be shifting received signals on the rig from their center frequency to your desired pitch, which will de-tune them; then re boosting them at your desired pitch with the outboard audio filter.

That's no problem with strong signals but it wouldn't be optimal for weak signals.
73, Drew AF2Z
    Drew So many filters are fixed at 700hz (because most older radios are) and I am nearly deaf at that freq.

I asked this question in hopes I wouldn't have to read 100 manuals and each review to try to pick the best one.

My rig is adjustable r374 inside the the 751a.

    I have a Kenwood and a Yaesu, both had internal jumpers/settings you could use to change the peak CW tone .

Mine were around 800-100o Hz ant that is too high for me so I changed them to 400 and 500 Hz to get out of the pink noise region to something easier to tune and listen to. .

When I tune a CW signal now, the peak S meter reading, with the narrowest filter in, corresponds to the strongest audio note too.

CW is Real Radio 73, John...K8JD
    I've been lurking on this thread and I am surprised that no one has suggested you build a "Resonant CW Filter"...Link to instructions below.

IMHO, this may be your answer.

I too have hearing issues...and having built 3 of these, 2 for 700 Hz and 1 for 800 Hz, I can honestly say they work better for me than any onboard radio filters or even the CALF filter.

Those only narrow down the bandwidth...a resonant speaker attenuates all frequencies except the tuned frequency.
Not to disparage onboard filters or the CALF filter but while they work very well they do tend to ring a bit especially when they are narrowed down.

A resonant speaker doesn't ring in my experience AND they are narrow banded.

So much so that you can effectively "Zero Beat" to the listening signal just by listening to the increase in volume when you find the sweet spot of the incoming signal.
I am amazed how well they work AND in fact my resonant speakers are my go to listening aid.

Also, while my CALF filter is an amazing device, IMHO the resonant filter is hands down the better choice for me.
Tuning was not a problem, I used the side tone from my radios to accomplish that task AND I have also used a signal generator too.
Try it, I doubt you will be disappointed and Good Luck.

73, AF5AF
    Rocky You seem to have figured out what I was trying to explain.

This is getting built right away.

I never heard of these.

I was leaning towards a passive audio filter (w3nqn) but was amazed at the questions/requirements his auto response mail gave me when I inquired about buying one of his units...several videos on line will help me get this speaker going...thanks a million..

Ray KF0AF 

Digital and CW

Just a tidbit of info about the different modes, and how sensitive/effective they are......
Using CW as a Effective distance reference baseline: ( signal strengths )
AM is -27dB 1/16
SSB -17dB 1/6
FM -14dB 1/4
RTTY -4dB 2/3
CW 0dB. 1
PSK31 +7dB X 2.5
FT8 +19dB X 9
JT65 +25dB. X 12
Amateur Radio....the Original Social Media
Richard Quick

    Very true.

When it absolutely MUST get through, nothing beats CW.

n1ea has recordings of the SOS from the MV PRINSENDAM (last SOS to be sent) up in the arctic.

I’ve listen to this until I can copy what is sent but WOW, those marine ops were good. the aurora noise is wild.

After reading everything I could find about this I am amazed that the powers that be have decided that we don’t need ship board radio ops who can copy code.
The only thing I know of that might equal CW is a quad phase Manchester code

It allows for really solid data signal but it doubles the bandwidth required.

Used on some deep space probes to maximize data continuity.

I don’t think I’d like to try to use it on HF.
Leslie Hock
    No surprises on that list.

The digital modes can get through when the others can't, but aside from my previous post about those modes being as interesting as watching paint dry, they provided little challenge to operators.
I've made quite a few 10M AM QSOs where I had to switch to SSB on receive to finish the rag chew due to changing conditions!
73 Mark K3MSB

    I quit doing the voice modes and switched to CW (first priority) and digital (plan B) because AM and SSB provided little challenge. 
Steve AI9IN

    I like CW & AM!

With transmitters DX-100, a Johnson Viking 1, a Globe Scout or a Knight T-60 to choose from who cares about digital?

I can listen on anything from an HRO-5 to an R-388, with some Heathkit, Hallicrafters and Hammarlund in between.

I'm playing now with the stuff I could dream about when I was a kid.
    So CW (MY mode) is not too hot or not too cold, It's Just Right

CW is Real Radio 73, John...K8JD
    Another thing between CW and all the other modes is the simplicity of a BASIC CW transmitter Vs what is needed the other modes. 
My first CW transmitter (homebrew) had a few resistors a few RF chokes, a few capacitors a handwound tank coil and onje tube and a few plug-in freq xtals.

The power supply had a small transformer, diodes and a capacitor.
Cost was whatever I paid for surplus xtals, a few bucks, the rest was stripped from an old failed TV receiver. 
To work the digital modes You need at least a laptop computer (I got a laptop for the XYL for $700) A mid to high end HF transceiver with CAT capability and good Freq stability (800 bucks if you get a good deal), Interface converters for radio to computer, and software to run it all.
Cost, aproaching $1500

CW is Real Radio 73, John...K8JD
    Agreed Mark.

Last week while on the road and listening to 2 meters, I was listening to a ham tell another ham how effective and exciting digital modes were.

That's all well and fine.

But then he went on to say that CW was not very efficient or effective when it comes to getting through on HF.

It was all I could do to keep my car on the road.

He went on to say that CW isnt very effective with the use of bandwidth and this is why the digital nodes were so popular.

I was looking for an opportunity to break in and politely correct him.

But after a few exchanges between the two hams, he confessed he was new to HF operations.

I think we all need to do a better job at getting the word out about how wonderful Charlie whiskey is.

One ham at a time perhaps.

The second ham operator said that maybe in a few years when the conditions were better he would attempt to learn CW.

I wish I had more time because by that time I was already at work and had to qrt.

I would have told him that regardless of the conditions this is one of the most effective modes there is.

I find no joy with ft8 or jt65.

If that's your thing, that's great.

But I'd like to know during a qso what's your gear is?

What's the weather like?

How long have you been a ham?

There's so much more then just watching a waterfall.

I'll grab a paintbrush and paint a wall just to watch it dry.

    He went on to say that CW isnt very effective with the use of bandwidth and this is why the digital nodes were so popular.
Digital modes are popular as you can increase your DXCC standings during periods of bad band conditions at the expense of other modes.

Bandwidth has nothing to do with it.
Mark K3MSB
    You can do digital for half that price or less.

And the software is free for a lot of it. 
Steve AI9IN

    I am not sure where the data is from but I question the figures.

If FM were better than SSB we would all be using FM for week signal voice.

If I understand the K1JT information correctly JT 65 gives about a 10 dB advantage over CW for EME.

A 25 DB advantage would mean EME is now a QRP operation.

I think the figures for CW verses JT65 are based on a 2500 KHz bandwidth whereas I am sure most are using much less than this for CW with brain adding some processing advantage.

For FM I suspect the number is based on signals above the threshold where the FM Signal Noise ratio starts to improve. 
73 Brian KF6C

    Friends, digital and CW.

CW is the most simple digital signal, on / off a.s.o.



Wire Signals in Use, January 1846

Have found evidence that Wire Signals were in use at least as early as January 1846.

This was only 19 months after the opening of the 1844 Baltimore-Washington "What hath God wrought?" line.

The event under discussion below the first reception of a telegraph message on the first line put in service after the 1844 line.

Below is the information on this subject, which I have entered into my chronological spreadsheet on the history of Wire Signals.

73 SW & (abram burnett)   


Letter of David Brooks to William Bender Wilson, Esq., dated March 1, 1880, published in The Telegraphic Historical Society of North America (Washington: Press of W.F. Roberts, 1895,) which volume contains the proceedings of the Society for 1895 . Brooks letter is in response to Wilson's request for information on first telegraph at Harrisburg. Brooks was one of four men on duty on January 8, 1846, when the first telegraph message was transmitted on this line. Brooks furnishes Wilson with a four page, first-hand account (pages 118-122) of that happening. Indeed, Brooks was the man who built the telegraph line late 1845, was in charge of it, put it in service in January 1846, and then took it down in March 1846.


In describing the events of January 8, 1846 (p. 119,) Brooks says: "In Mr. Vail's pamphlet, he gave a few signals or abbreviations, '34' was to make dots to enable one to adjust the relay. Hepburn [at Lancaster] often sent them [Reid and Hughes at Harrisburg] 34. Both offices were crowded with people curious to see its operation. Questions were sent and answers received to gratify their curiosity. When Reid sent word to Hepburg to tell the ladies in Harrisburg what kind of weather there was in Lancaster, Hepburn would send him 34. Hepburn would set Reid to making dots. While Reid was making dots, Hepburn could the better read his novel and enjoy his cigar."


This is the earliest mention of Wire Signals being used in telegraphy.


The question then becomes, what was "Mr. Vail's Pamphlet" ?


"Mr. Vail's pamphlet" was probably some booklet assembled ad hoc for the first telegraph operators, which has been lost. The only known publication by Vail prior to this date (January 1846) was his 24-page booklet published in 1845 and titled Description of the American Electro Magnetic Telegraph Now in Operation Between the Cities of Washington and Baltimore, by Alfred Vail, Assistant Superintendent of Elec. Mag. Tel. for the U.S. (Washington: J. & G.S. Gideon, 1845.) This 24-page booklet does not contain any Wire Signals.


Vail's next publication did not appear until 1847 - The American Electro Magnetic Telegraph with the Reports of Congress and a Description of All Telegraphs Known, by Alfred Vail (Philadelphia: Lea & Blanchard, 1847.) This 208 page book does not contain any wire signals.


Therefore, one concludes that "Mr. Vail's pamphlet," to which David Brooks alludes, was an instruction paper of some kind, "got up" for the first operators, whether printed or hand-written. No known copies of this "Mr. Vail's pamphlet" survive.


However, the important thing is that Brooks' statement indicates there were Wire Signals in use as early as January 1846.Unfortunately, "34" is the only original Wire Signal known at the present day.

Pravoslavna SlowSpeedWireGroup



Has nothing to do with CW

When I was young, I got from my father a compass box with various passers .

All passers have the heading J.J.T. & S. (& Sons)

Some articles have the caption 1943.

It appears that this was originally used for location or navigation using maps.

I wrote museum Museum Boerhaave, collections and received the following message

Conservator, Tim Huisman reports: Suppose it's this:





Hello friends,

BBC Radio 4 - The Life Scientific, Lucie Green on the sun.

Interesting but just an outline of the subject, you can download the program here:

Have a nice day gents, BCNU.

73, Yann, F5LAW SideSwiperNet Group

By OM Yann F5LAW


73, from the town at the rivers "De Bergsche Maas" and "De Dongen" Geertruidenberg (800+ years city rights) at: 51.702211N 4.853854E

Editor Jan Pieter Oelp PA3CLQ



My simple website about Gigantic DF-Antennas

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