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Re: Just curious. . .
¿ªÔÆÌåÓýYou gain some slow memory to store stuff in¡ ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of Duane B via groups.io
Sent: Wednesday, April 16, 2025 10:45 PM To: [email protected] Subject: [SoftwareControlledHamRadio] Just curious. . . ? But do you gain anything by populating 1 or 2 of the 8Mb SPI memory chips on the Teensy?? Or do you loose? some functionality by doing that? ? Just curious. ? Thanks, Duane - K5CA |
Re: New book
Yeah, I did too, but twice received the wrong book. I have redone the submission from scratch and I should be hearing within 72 hours. It will have a new ISBN number, which means we lose all of the nice reviews we had up until now. To all those who took the time to say nice things about the book, a huge Thank You from Al and I. I will post when the new book is ready to ship. Meanwhile, they have been good about taking books back. Jack, W8TEE
On Wednesday, April 16, 2025 at 09:14:16 PM EDT, John Owens K1JO via groups.io <johnowenschina@...> wrote:
I just received the wrong one, the old one that I already have :(
Strange, as I waited until the purchase page had the new cover with the black T-41.
John K1JO
-- Jack, W8TEE |
Re: No SSB output
Yes they are. Step through the circuit starting at the audio hat. Do you see the 750 Hz audio tone on the I and Q outputs of the audio hat? Then, walk through the transmit chain on the RF board and find where the signal disappears.
On Wednesday, April 16th, 2025 at 7:45 PM, Tim via groups.io <w4yn@...> wrote:
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Re: New book
Oddly, two people have written that they received the right book. Even harder to figure out now. I just went through the entire process again and updated everything, including the ad narrative (which has 4SQRP still selling a kit). I should get word back within 72 hours that all is well. The bad news is that about 165 very good book reviews will no longer be tied to the book...it starts over. Jack, W8TEE
On Wednesday, April 16, 2025 at 01:38:14 PM EDT, Greg KF5N via groups.io <greg.electricity@...> wrote:
Amazon needs to be hammered on again.? They are not getting it done correctly.
?
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73 Greg KF5N
-- Jack, W8TEE |
Re: New book
Glad to hear it...thanks! Jack, W8TEE
On Wednesday, April 16, 2025 at 02:44:53 PM EDT, Duane B via groups.io <dbrantley@...> wrote:
I did, finally, receive a copy of the NEW book.? Received it last week.? I meant to post up about it but had a senior moment and forgot too.? Amazon even told me to keep the old copy.
?
Duane - K5CA
-- Jack, W8TEE |
T41-2 and K9HZ Power Amplifier Measurements
I've been working on a system to accurately evaluate HF linear power amplifiers.? It took quite a while to figure out how to get the system working.
Here's the first tangible results in the form of a spreadsheet: There are 3 worksheets.? The first "PA out cal" is nothing more than measurements between reference plane 1 (PA output), reference plane 2 (radio output), and the input of the power meter.
Sheet #2 is the "Small Balun" version of the T41-2 Power Amplifier (final + driver).? Sheet #3 is the K9HZ amplifier I built here a couple of years ago.
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PEP output powers are not as high as expected.? Remember to halve the PEP numbers to get average power.? Quite low!
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Note that the K9HZ PA drops to below 2 watts average power on the higher bands.? The amplifier was tuned up according to the build instructions.
The critical thing seems to be the bias current for the final transistors is probably too low at 250mA each.
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I've seen comments by others that the part used in the final amplifier (Mitsubishi RD16HFF1) needs quite a bit of quiescent bias current for decent linearity.
Thus I've tuned the T41-2 Power Amplifier to a bias of 700mA each.? You can see the total current drain in the last column of the measurements.
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I would be interested to compare my measurements to other's evaluations.? Here is a video summary of the measurement system and procedure:
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The system:
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The measurement procedure:
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73 Greg KF5N |
Re: New book
Nor should you. But the problem is that the ad shows the new cover: and I can't figure out how that happened since we updated it April 4th. After 2.5 hours on the phone with Amazon and Kindle Direct, they don't know either. Jack, W8TEE
On Wednesday, April 16, 2025 at 01:17:32 PM EDT, Greg KF5N via groups.io <greg.electricity@...> wrote:
I want a new copy, but I'm not going to order one from a page which says April 18 2024.
?
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73 Greg KF5N
-- Jack, W8TEE |
New book
ALL: Has anyone received a copy of the new T41 book? The new version supposedly became available after April 4th and has a black T41 on the cover and Appendix C on Calibration has been expanded to a new chapter (#20). If so, please let me know, as I have ordered review copies for Al and myself twice now, and they have sent the old pre-April 4th version. Thanks! Jack, W8TEE -- Jack, W8TEE |
Re: No SSB output
Display is not showing anything. will dig deeper. TNX Tim ? Tim O'Rourke W4YN@... Low Power Amateur Radio Rocks Member of Flying Pigs,ARCI,GQRP,RSGB,ARRL Life Member R/C Pilot (sort of) NRA Life Member NRA Certified Rifle, Pistol, Black Powder Instructor, Range Officer -----Original Message-----
From: <[email protected]> Sent: Apr 16, 2025 12:13 PM To: <[email protected]> Subject: Re: [SoftwareControlledHamRadio] No SSB output ? If you take the Mic wires off the pins on the hat and just place your finger on Hat PIN 4 and key the radio, you will see a 60 cycle pattern in the display and hear that in the transmitted signal.? If not, there is something up with either the firmware, a selection in the menu (try a different EQ), or the hat itself. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of Tim via groups.io ? No sir ? ? ? |
Re: No SSB output
¿ªÔÆÌåÓýIf you take the Mic wires off the pins on the hat and just place your finger on Hat PIN 4 and key the radio, you will see a 60 cycle pattern in the display and hear that in the transmitted signal.? If not, there is something up with either the firmware, a selection in the menu (try a different EQ), or the hat itself. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of Tim via groups.io
Sent: Wednesday, April 16, 2025 11:08 AM To: [email protected] Subject: Re: [SoftwareControlledHamRadio] No SSB output ? No sir ? |