Posts

Self Inflicted Wound

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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...

A magical re-appearance !

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I was doing my usual Saturday backup of the blog to Archive.org and noticed this: Previously as mentioned here: https://wb9kzy.blogspot.com/2025/08/bunker-of-doom-doomed.html  the August 2 and 9 backups were missing but now they are back, the internet is magical !  (and I DID do the backups) Unfortunately the Bunker of Doom site is still gone. Best Regards, Chuck, WB9KZY http://wb9kzy.com/ham.htm   

Micah Parsons

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This is big news in NE Wisconsin - the Packers have traded Kenny Clark and two future 1st round draft picks to the Cowboys for Micah Parsons.  I have mentioned Micah Parsons before: it's really true ! https://wb9kzy.blogspot.com/2024/01/micah-stay-away-from-our-qb.html  Of course the Packers had Aaron Jones, 33, to take care of Micah Parsons in that game.  The Packers crushed the Cowboys that game and Micah wasn't really that effective.  And now Aaron Jones plays for the Vikings and Micah and the Packers will have to face him twice. People are comparing Micah Parsons to Reggie White.  Reggie always seemed able to pick just the right time and make big plays like a QB sack, fumble or even a lateral to Leroy Butler for the first ever Lambeau leap. If Micah Parsons can match Reggie in clutch performances he will be worth every penny and the Packers will win the Superbowl ! BTW the only other Micah I remember was a fictional character, Micah Torrance on The Rifleman ...

"Oh Dennis !"

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I was listening to  The Jack Benny show - October 12, 1947: https://archive.org/details/OTRR_Jack_Benny_Singles_1947-1948/JB+1947-10-12+Jack's+Sponsor+Buys+Insurance+On+Him.mp3  Usually the random access ability of the music player on the phone lets me skip the songs (also the commercials, especially the Lucky Strike commercials, they are insidious) of Dennis Day or Kenny Baker but this time I listened to Dennis (about 14:25) sing: Ya Sure — You Betcha (Ay Ban Tank Ay Do) Hilda, oh Hilda, Ay ban tank you're grand. Will you oh will you let me hold your hand? If Ay should ask you, do you love me too? Say ya sure — you betcha. Ay ban tank Ay do. Oh Ay do, yes Ay do. By golly, by yimminy Ay do. If Ay should ask you, do you love me too? Say ya sure — you betcha. Ay ban tank Ay do. In Wisconsin Ole Johnson Fell in love with a sweet Swedish miss, Hilda Swanson. He wooed her, he pursued her. From Wisconsin her Johnson sings Swanson this song: Hilda, oh Hilda, Ay ban tank you're ...

LT1252 as a preamp ?

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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 

Bing redeemed itself via a redemption ?

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I mentioned kind of giving up on Bing: https://wb9kzy.blogspot.com/2025/08/giving-bing-rest.html  Well after about 2 weeks of very little usage of Bing the stragety worked !   I was finally able to donate my points to charities: One thing is that I switched my VPN from a server in D.C. to a server in CA - maybe that helped ? Tomorrow I will see if Bing is limiting me as far as earning points.  Hopefully earning points without having to wait 30 minutes between sessions is now in effect.  I would like to be able to use points to extend my Windows 10 computers for another year of security updated. But maybe I'll just continue slacking off on Bing, as I said before it's probably easier to just send money to the charities than slaving away for Bing points (which are worth 1/10 of a cent for each point?). Update 2025-08-27: seems like I'm still being limited by Bing :( Best Regards, Chuck, WB9KZY http://wb9kzy.com/ham.htm 

Time for FreeDV QRP ?

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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 ...