More comprehensive Schematic by KD4SGE & WA4ITD
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More comprehensive Schematic by KD4SGE & WA4ITD
It´s not just a schematic, drawn by electronics professionals, it also shares some other useful information in only one document.
Thanks to KD4SGE & WA4ITD for their work and thanks for sharing it with us:
*03. August 2022* Updated Version
https://dl2man.de/wp-content/uploads/20 ... _v1.0m.pdf
Since forum software is restricting maximum file size, I uploaded it to my main page and shared the link.
73 Manuel; DL2MAN
Thanks to KD4SGE & WA4ITD for their work and thanks for sharing it with us:
*03. August 2022* Updated Version
https://dl2man.de/wp-content/uploads/20 ... _v1.0m.pdf
Since forum software is restricting maximum file size, I uploaded it to my main page and shared the link.
73 Manuel; DL2MAN
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Re: More comprehensive Schematic by KD4SGE & WA4ITD
Glad to see this work endorsed, good job Manuel!
73,
Robert, WA2T
73,
Robert, WA2T
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Re: More comprehensive Schematic by KD4SGE & WA4ITD
Great Manuel, superb work
VU2SPK
Shanks
India
VU2SPK
Shanks
India
73's
de
VU2SPK
Mysore India
de
VU2SPK
Mysore India
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Re: More comprehensive Schematic by KD4SGE & WA4ITD
When I try https://www.youtube.com/watch?v=jlmurYa7SOg I get "no longer available"
I remember a video that showed the piezoelectric effect that tapping the caps had on the audio but was there a video about a mod that cured that?
Thanks
I remember a video that showed the piezoelectric effect that tapping the caps had on the audio but was there a video about a mod that cured that?
Thanks
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Re: More comprehensive Schematic by KD4SGE & WA4ITD
Video was not by me.... And I documented a possible fix here in the forum:Ohwenzelph wrote: ↑17 Aug 2022, 09:41 When I try https://www.youtube.com/watch?v=jlmurYa7SOg I get "no longer available"
I remember a video that showed the piezoelectric effect that tapping the caps had on the audio but was there a video about a mod that cured that?
Thanks
viewtopic.php?p=2863#p2863
The 0803 Tantalums helped, but were very hard to replace.
The linked 470nF 0603 Tantalums are a drop in replacement and greatly reduce microphonics effect.
Watch for polarity
73 Manuel; DL2MAN
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Re: More comprehensive Schematic by KD4SGE & WA4ITD
How closely should the 470nF C25-28 caps be matched to keep the two sides of the Tayloe detector tightly balanced? I ask because the 0603 tants are 10% tolerance. And pricey if getting a bunch. Tnx
P.S. on the enhanced schematic, main board, page 2, the values for C24 and C30 are listed as 100n but should be 1n
P.S. on the enhanced schematic, main board, page 2, the values for C24 and C30 are listed as 100n but should be 1n
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Re: More comprehensive Schematic by KD4SGE & WA4ITD
Ohwenzelph, thanks for the feedback. I am in the process of correcting a few other goofs and expanding on the schematics to include separate RF board schematics for the new Classic and Lo band options.
As for the 470nF and tolerance: The capacitors are part of an RC filter. A 10% change in capacitance will cause a 10% change in the detector bandwidth. If the capacitors vary from each other by 10% you will get a distortion at the edge of the detected bandwidth. So using +/-10% capacitors will affect the audio bandwidth by +/-10%. A rough calculation of the (tr)uSDX bandwidth based on 50ohms and 470nF suggests a bandwidth of 3.38kHz +/- the tolerance of the capacitors used. And since the tolerance was not specified in the main board BOM, it can be assumed that 10% will be fine.
If you are interested in learning more about the Tayloe Detector:
Dan Tayloe wrote a paper on the detector:
http://www.norcalqrp.org/files/Tayloe_mixer_x3a.pdf
And a theses paper by Zenaneh Kebede provides a more in-depth view
https://researchrepository.wvu.edu/cgi/ ... ontext=etd
73
Richard, KD4SGE
As for the 470nF and tolerance: The capacitors are part of an RC filter. A 10% change in capacitance will cause a 10% change in the detector bandwidth. If the capacitors vary from each other by 10% you will get a distortion at the edge of the detected bandwidth. So using +/-10% capacitors will affect the audio bandwidth by +/-10%. A rough calculation of the (tr)uSDX bandwidth based on 50ohms and 470nF suggests a bandwidth of 3.38kHz +/- the tolerance of the capacitors used. And since the tolerance was not specified in the main board BOM, it can be assumed that 10% will be fine.
If you are interested in learning more about the Tayloe Detector:
Dan Tayloe wrote a paper on the detector:
http://www.norcalqrp.org/files/Tayloe_mixer_x3a.pdf
And a theses paper by Zenaneh Kebede provides a more in-depth view
https://researchrepository.wvu.edu/cgi/ ... ontext=etd
73
Richard, KD4SGE
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Re: More comprehensive Schematic by KD4SGE & WA4ITD
Is C44 in the 60m filter supposed to be 220p instead of 470p? Original schematic has it as 220p.
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Re: More comprehensive Schematic by KD4SGE & WA4ITD
Hi Guys,
The schematic is a really nice drawing and perfect documentation. Many thanks to the author.
How about the Software Defined Radio. Is there a similar document with block diagram available? That helps to understand the remaining part of the radio, e.g. TX modulation.
Best
Tobias
The schematic is a really nice drawing and perfect documentation. Many thanks to the author.
How about the Software Defined Radio. Is there a similar document with block diagram available? That helps to understand the remaining part of the radio, e.g. TX modulation.
Best
Tobias
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Re: More comprehensive Schematic by KD4SGE & WA4ITD
On the second page under “Taylor Quadrature Sampling Detector” what is labeled as C35, off pin 16 of U6, I believe, should be labeled C20.
(the actual C35 is on pin 16 of U5.)
73
(the actual C35 is on pin 16 of U5.)
73
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Re: More comprehensive Schematic by KD4SGE & WA4ITD
Hello,
On the schematic with the "classic" band LPFs, in the 20m filter L31 is labeled 100nH with 9 turns. However L32 is labeled 144nH, at 6 turns. How can fewer turns yield more inductance? Also, in some of the other filters, 100nH is listed at 5 turns. All cores are listed as T37-2.
I suspect either the inductance values are after spreading/compressing the turns and then measuring, or L31 has a typo.
Any help?
Tnx
Bob WB0POQ
On the schematic with the "classic" band LPFs, in the 20m filter L31 is labeled 100nH with 9 turns. However L32 is labeled 144nH, at 6 turns. How can fewer turns yield more inductance? Also, in some of the other filters, 100nH is listed at 5 turns. All cores are listed as T37-2.
I suspect either the inductance values are after spreading/compressing the turns and then measuring, or L31 has a typo.
Any help?
Tnx
Bob WB0POQ
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Re: More comprehensive Schematic by KD4SGE & WA4ITD
The cores for 20m on the classic board should be T37-6 yellow cores, not -2 reds. That's clearly an error. The -2s are only spec'd up to 10mhz (30m). They will work at higher frequencies but at reduced performance. I suspect the other items you mentioned are also typos.
73
KA1FT
Brian
73
KA1FT
Brian
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