A Crummy Commercial

Three unusual things I noticed on Saturday.  First: I got an email from a "person" who was interested in this: This was the ema il: The email seems off, written by a machine ?  Or possibly  a machine translation ?  I can't remember ever using the word: semantics in an email subject line. Two other things: there is a mistake on the 6 bit D/A => no path for current to ground or VCC.  A resistor to ground would work.  I removed the 6 bit D/A schematic from the zip on the projects page. I foolishly replied to the email with this so maybe I have been marked as a sucker ? Another thing: the schematic was on a scraped data page found with this search:  "Fm Radio Circuit Diagram Pdf"   But a few hours after my email reply that 25 year old 6 bit D/A circuit diagram had disappeared ! Very weird, so possibly this email was from the goomer who runs that site or they just rotate their filched content regularly ?   I never heard back from...

I was paging through the October 2025 QST online when I came upon this on page 94: Really unexpected but a pleasant surprise !  I took that picture in June 1975 with my Olympus 35RC.  When the Glen Gates Gang Field Day entry was sent in the picture got included.  Somewhere around here I've got a plastic bag with several copies of that issue - I remember going over to Amateur Electronic Supply (on Fond du Lac in Milwaukee) and buying them.  I've mentioned the November 1975 cover before: https://wb9kzy.blogspot.com/2022/06/field-day.html  The picture reminded me of Scott Tilton who died this year: https://wb9kzy.blogspot.com/2025/04/a-novice-trio-no-more.html  Scott was the brains behind repurposing the tower to a transportable unit.  It's a shame that Scott's article for the tower wasn't published. Here's the Glen Gates Gang page with more of my pictures from Field Day: http://wb9kzy.com/ggg.htm  The fact that that magazine cover was from almost 50...

I got an email from a ham asking about the Ultimatic keying mode.  I did a brief text file on Ultimatic: http://wb9kzy.com/ultimat.txt  I did invite comments so emails are fair.  It turned out that this ham had a K1EL K45 keyer and a Yaesu FT-991a.  The Yaesu doesn't have Ultimatic as an option for the internal keyer.  The emailer wanted to know what could be done to send with Ultimatic on the Yaesu. I replied that the emailer should contact K1EL but that it was just a matter of buying of making up a keying cable between the keyer and the rig.  Also, the Yaesu menu would have to be set for straight keying. This reminds me that my kits (and site) may not be that beginner friendly in the same way that a Knight-kit or Heathkit was.  This is also probably why so many already built wire antennas and cable sets are sold, I guess it wouldn't occur to me to buy such things :) Also, when I became a ham most people weren't self taught.  I learned from local...

 I saw this on the Digikey site: The PVI is no longer made ?  It's the heart of the Keyall HV and Keyall HV+.  I looked at the suggested replacement, it is surface mount but DigiKey doesn't sell it :(   This is a problem with the DigiKey notification system, if it's a part that hasn't been ordered recently, DigiKey doesn't send a notification.  I guess it's better than Mouser, they don't send anything at all.   Best Regards, Chuck, WB9KZY http://wb9kzy.com/ham.htm 

In a recent blog post the Koss Headset with a built in USB port was mentioned: https://wb9kzy.blogspot.com/2025/08/time-for-freedv.html  For no good reason I did look on Ebay and bought one: It was listed as NEW but really more like: "new ?"  and there was a slight "air" about it. it was out of the box at least once before I got it Oh well, the seller did mail it as I wanted.  The headset is comfortable although I'm not sure how much I can bend the microphone stalk.  It also sounds fine and it seems to record OK although with a little hum.  I'm not sure if there are any adjustments, there aren't any instructions in the box or on the Koss site.  It really was plug and play - after plugging in the SB-45 I was able to hear mp3 files and record a voice message without doing anything other than opening the mp3 player and voice recorder, nice. I'm partly prepared for FreeDV - it's already September, really need to put up at least some kind of antenna !...

Continuing with the filter test saga from yesterday: https://wb9kzy.blogspot.com/2025/08/self-inflicted-wound.html  I dug out the Si5351 breakout board on a solderless breadboard connected to an Arduino Nano. After a few misadventures with the Arduino IDE and the Skyworks Clockbuilder I was able to generate this: Unfortunately it is wrong, I wanted 27.005 MHz (CB channel 4) but punched in 27.05 instead and of course the silly software did exactly what I punched in :) Re-doing the frequency with Clockbuilder I got this: This is after being peaked through a double tuned LC filter, yikes !   Finally able to peak the filter - but while I was wrestling with the Arduino and Clockbuilder I remembered the NanoVNA:  isn't filter work the exact reason for having a NanoVNA ?  And doesn't it already have an easy to program Si5351 (or equivalent) inside ? I tried listening to the 27.005 carrier on the K2, double yikes !  Really sounds terrible (although strong) but hope...

I was attempting to peak up a double tuned LC bandpass filter for the 10/11 meter bands when I looked at my scope: The reading isn't 30 MHz as the DDS display says, it is 20 MHz.  That's not going to work, Chuck.   I popped the cover off the DDS and bingo, there is the reason: see the square can marked: 50.000MHz ? This is an AD9850 DDS design by Curtis Preuss, WB2V, in QEX of July 1997.  The firmware was modified by me but only in superficial ways.  The problem is that the clock to the AD9850 DDS is only 50 MHz.  A DDS can be expected to output a decent signal but only up to less than 1/2 the clock frequency.  If an attempt is made to specify a higher frequency than 25 MHz in this case either the firmware should flag that OR ??  See the PIC code on the projects page: http://wb9kzy.com/projects.htm    The PIC asm code in a zip:  http://wb9kzy.com/siggen3b.zip    Back to the drawing board, I suppose I could change the firmw...

I found a 20 db wideband amplifier based on the LT1252 amplifier.  I tried using it to boost the received signal from my 11 meter beacon on CB channel 4.  It certainly makes the signal noticeably stronger but seems to boost the noise just a little more than the signal, so no help.  Here is the LT1252 amp in a round Altoids tin: I will have to see if there are any "low noise" versions of the LT1252.  I suspect not, all of those active devices in that "op amp" configuration probably not going to ever be as good as a single device as far as noise.  But the LT1252 is very stable - I recall that some kit designers use one in ham radio rigs as a transmitter driver to make the kits more stable. https://www.analog.com/en/products/lt1252.html  Best Regards, Chuck, WB9KZY http://wb9kzy.com/ham.htm 

This video on Marxy's blog was interesting: https://blog.marxy.org/2025/08/freedv-radev1-comared-to-sideband-at.html  560 km or about 350 miles apart on the 40 meter band during the day.   FreeDV exhibits that just above the noise "perfection" of a digital mode.  As long as there isn't too much fading it looks very promising.  The narrowness of the FreeDV RADE V1 signal is amazing - no one could complain about it's width, especially at such low power levels. At first I was wondering about the relatively low power levels used for SSB in the video.  But then I realized that when the "Bart head" is transmitted (digital transmissions all look like the top of Bart Simpson's head in the frequency domain) it's like going key-down CW or RTTY, in other words a 100% duty cycle.  SSB is generally much lower at 20 to 50% duty cycle so SSB is much less taxing on the transmitter than a key-down mode like RTTY.  I suppose a comparison of the signals might have ...

Seems like another nifty tech oriented website is gone ?: http://www.bunkerofdoom.com/  Luckily there are a number of hits on the wayback: https://web.archive.org/web/20240521124557/http://www.bunkerofdoom.com/  On a related note, I heard about this software: https://www.httrack.com/  A way to fully copy a site to a drive and then be able to look at it offline.  Might be useful for backing up the Jackson Harbor Press site or maybe even for this blog ?  One thing about a wayback archive is that there are often "holes" - pictures just aren't always preserved.  I remember a friend challenging the notion of backups once:  "do you fully verify the backup ?"  -  honestly, no.  I've been subscribing to the concept: " do lots of backups and hope that the aggregate will have everything " :) Also, something weird happened to a couple of backups I did manually to the wayback of the blog: I usually do them on Saturday of the previous 7 days of blog ...

I was having trouble with a couple of weak stations.  The first was WDOR-FM, 93.9 MHz, the station I listen to the Brewers on.  One night the signal got noisier and noisier - then I realized that the rabbit ears (from an old TV set) with a shorting wire to make them a loop was the problem.  So I removed the shorting wire and then shortened up each each of the rods to 30 inches (half of the roughly 5 foot long antenna from 468 / 93.9).  This was audibly better ! BTW, I stopped trying to catch the Brewers games on the originating station, WTMJ 620 in Milwaukee (180 miles away) which isn't as strong as WDOR-FM in Sturgeon Bay (50 miles away). Next I was having trouble hearing my 11 meter thermometer beacon on CB channel 4 (27.05 MHz).  So I made up a quick indoor dipole by using the 468 / f formula again.  Made the dipole from some old twisted pair and the remaining skinny coax from MFJ. it was a nicely made thingy but I was never going to use it with an HT in...

I did a search using Duck Duck Go for:     pn5179 ham radio circuit schematic (I just happen to have a bunch of PN5179 transistors in the junkbox). And one of the links was: https://www.edaboard.com/threads/pn5179-equivalent-transistor-needed-for-construction.259327/  where I saw this: Ah, the little guy with the hammer !  That's from the QRP Popcorn blog.  So I tried looking at the QRP Popcorn blog and got this: Some of the QRP Popcorn pages are found almost completely intact on archive: https://web.archive.org/web/20241226034145/http://qrp-popcorn.blogspot.com/2022/10/some-analog-ic-gilbert-cell-mixer-notes.html  But I noticed that on some other pages, pictures and diagrams are missing, bummer ! BTW I also tried a search for: "Discrete BJT Transformerless Feedback Amp" (the title on that PN5179 circuit) and nothing - I was interested in seeing his comments on the circuit. Also, I didn't see any of his videos on Youtube either.  I'm hoping it's j...

I got another part discontinuation email from DigiKey today.  I've seen the BF256B notice three times now, first in January and then in June - I guess it's good they repeated them because I didn't remember the exact number. https://wb9kzy.blogspot.com/2025/01/these-are-never-good-news.html  https://wb9kzy.blogspot.com/2025/06/another-one-bites-dust.html  However this time they also included the MMBF5486 which is a surface mount JFET, so it's not just the TO-92 parts, in other words, it's not just leaded parts, also surface mounted parts. On a different note, I was looking at the 2SK-152 JFET mentioned here: https://wb9kzy.blogspot.com/2022/09/sony-2010-jfet-problems.html  I noticed an interesting grounded gate amplifier circuit on the data sheet.  Did a little more searching and found a datasheet with better resolution here: https://www.silicon-ark.co.uk/datasheets/2sk152-datasheet-english.pdf  Here is a screen shot: The datasheet is also available in this ...

Myron Cook has a lot of enthusiasm for geology, it's easy to see that - and this video was no exception: source:  https://www.youtube.com/watch?v=906cxbrk_yM  He enjoys being outside and making observations.  And then his videos communicate that to the viewer by weaving them into an explanatory story.  Either Myron has help or he is a wiz at video, too, because the presentation is first rate.  The use of drones is particularly effective for communicating the scale of the formations.  This shot of Myron walking across these limestone / gypsum formations was particularly cool: It reminds me of the flagstone driveway and patio we had when I was a kid in Fox Point in the 1960s.  Only these "flagstones" are maybe 100 times the size. I took an Earth Science class as a freshman in high school.  The teacher was Alden Larson who also had that enthusiasm for his subject.  Sometimes we got out of the classroom, once we did a cross section of the Milwauk...

I mentioned code for PICs recently: https://wb9kzy.blogspot.com/2025/07/the-code.html  Today I received an inquiry about the Norcal keyer chip: the PIC12F629-I/P is programmed by me to become the Norcal Keyer chip http://wb9kzy.com/norcal.htm  The ham then mentioned that he had built a home brew version of the Norcal Keyer kit for a beacon project but it didn't work.  He didn't realize that the PIC chip he had purchased was blank and wouldn't do anything until it was programmed.  So he just wanted to check that I still sell the chip.   When I heard this I offered to program the chip he had bought at no charge other than the normal  shipping fee (now $5 in 2025).  I can see where a customer might not want the hassle of packing up and sending the chip to me for programming but I thought I'd offer. I'll put something on the web site about this later but I also offer this service to customers in general:  if you would like me to program YOUR chip...

Not really but sometimes Farnsworthing Morse Code causes problems.  Farnsworthing is sending Morse Code at a relatively fast speed with exaggerated spacing in between the characters to result in a lower overall speed.  W1AW does this during code practice at slow speeds to prevent the listener from "counting".  5 WPM code practice is sent at 15 WPM with extra spaces. https://www.arrl.org/code-practice-files  https://www.arrl.org/files/file/Technology/x9004008.pdf  You want to hear/recognize each Morse character as a sound, counting the dits and dahs will work up to a point but it slows you down.  Kind of like reading out loud (aka moving your lips) is slower than reading silently so teachers discourage young readers from verbalizing what they are reading. A customer had a problem with his Island Keyer II keyer (http://wb9kzy.com/ik2.htm) .  He was trying to record:   QRL?  into a memory.  But the Island Keyer II wasn't recording the quest...

I have been using this W1FB JFET preamp design from March 1979 QST: Here it is in a tin: The problem is that while it does amplify it also oscillates and that makes it hard to tune up.  However I found this design: source: https://www.qsl.net/wn5y/ra01042.htm  project: https://www.qsl.net/wn5y/ra01000.htm  This WN5V receiver was available from the now defunct BG Micro: I've never tried a grounded gate (or base) amplifier before but apparently they are often more stable.  Now to actually try it ! Best Regards, Chuck, WB9KZY http://wb9kzy.com/ham.htm