On Tue, Nov 5, 2019 at 03:49 PM, Bob Macklin wrote:
That wouldn't be a problem using a DDS VFO.
Bob, I was responding to Gary WB6OGD when he said "On the other hand if you are adding a VFO to a NC-40 I don't know why...? the NC-40 is amazingly stable and usable." He says he doesn't know why one would want to add a? DDS VFO to the NC40A, I replies with "Full band coverage would be nice."?
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On Tue, Nov 5, 2019 at 03:40 PM, wb6ogd wrote:
Below that they go too fast for me
DXpeditions and DX in general sometimes hang out down there.
above that is only the digital modes and the novice band.?
I like the Novice band
Why would you want more than that?
Frequency agility is a nice thing to have
If I did want more, a simple tap on the toroid with a switch would do the job just fine I would think...
But a DDS VFO that covers everything very inexpensively and very conveniently would do the job a lot better.
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You could replace the crystal filter with a LC filter if you want wider BW.
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And you can build this basic design with a single crystal at the expense of wider skirts on the IF filter. But you might be able to do RTTY with 170Hz shift.
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And a 9850 or 5351 could produce the two frequencies for RTTY.
?
Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"?
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----- Original Message -----
Sent: Tuesday, November 05, 2019 3:40 PM
Subject: Re: [qrptech] DDS VFO!
My NC-40 (homebrew copy) tunes 7014-7066.? Below that they go too fast for me, above that is only
the digital modes and the novice band.? NC-40 filter is too narrow for SSB (though I have listened to
some canadians and you can mostly understand them but with very bad quality).? Why would you
want more than that?? If I did want more, a simple tap on the toroid with a switch would do the job
just fine I would think...
73,
Gary
WB6OGD
On 11/5/2019 2:19 PM, Mike M6MST wrote:
On Tue, Nov 5, 2019 at 02:03 PM, wb6ogd wrote:
if you are adding a VFO to a NC-40 I don't know why
Full band coverage would be nice.
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That wouldn't be a problem using a DDS VFO.
?
Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"
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----- Original Message -----
Sent: Tuesday, November 05, 2019 3:25 PM
Subject: Re: [qrptech] DDS VFO!
On Tue, Nov 5, 2019 at 02:46 PM, Bob Macklin wrote:
What do you mean by "FULL BAND COVERAGE"?
7000 kHz to 7300 kHz? My Wilderness NC40A only covers about 40 kHz.
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My NC-40 (homebrew copy) tunes 7014-7066.? Below that they go too
fast for me, above that is only
the digital modes and the novice band.? NC-40 filter is too
narrow for SSB (though I have listened to
some canadians and you can mostly understand them but with very
bad quality).? Why would you
want more than that?? If I did want more, a simple tap on the
toroid with a switch would do the job
just fine I would think...
73,
Gary
WB6OGD
On 11/5/2019 2:19 PM, Mike M6MST wrote:
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On Tue, Nov 5, 2019 at 02:03 PM, wb6ogd wrote:
if you are adding a VFO to a NC-40 I don't know why
Full band coverage would be nice.
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On Tue, Nov 5, 2019 at 02:46 PM, Bob Macklin wrote:
What do you mean by "FULL BAND COVERAGE"?
7000 kHz to 7300 kHz? My Wilderness NC40A only covers about 40 kHz.
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What do you mean by "FULL BAND COVERAGE"?
?
Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"
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----- Original Message -----
Sent: Tuesday, November 05, 2019 2:19 PM
Subject: Re: [qrptech] DDS VFO!
On Tue, Nov 5, 2019 at 02:03 PM, wb6ogd wrote:
if you are adding a VFO to a NC-40 I don't know why
Full band coverage would be nice.
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There is no reason the 49er VFO could not be made to work with any of the NorCal transceivers. I have several NorCal40 boards and the boards for a NorCal Sierra.
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I have suggested to Jack that he make the 49er VFO PCBs available again.
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It's a better design than the QRP Labs VFO even though I only works with a AD9850.
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I like the fact it has the USB serial port and uses a serial LCD.
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I want the serial port for CAT operation.
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And I am trying to learn how to use "OmniRig" to allow keying and CAT operations on the same serial port. But one problem is that the Arduino design uses the USB serial RTS for reset to activate the bootloader.
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If you want both Tx enable and the key on the same port it will take two serial ports.
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My design does have two USB serial ports. One connected to the 328 for the CAT operations and the second for a keyer. And my USB serial ports are optically isolated.
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Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"
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----- Original Message -----
Sent: Tuesday, November 05, 2019 12:52 PM
Subject: Re: [qrptech] DDS VFO!
On Tue, Nov 5, 2019 at 11:52 AM, ajparent1/kb1gmx wrote:
FYI the 49er VFO design, the supplier apparently stopped making it.
Are you talking about the Jack Purdum / Farrukh Zia board? If so Jack mentioned in the SoftwareControlledHamRadio group that there are lots of boards out there based on their design. Might be worth looking into as Farrukh has gone somewhat MIA. I have one of
these kits and a 49er kit from eBay but if it will work with the 40A I may just have to save the VFO board for that!
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Re: Do you have a favorite home brew short wave receiver to build with scouts?
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On Tue, Nov 5, 2019 at 02:03 PM, wb6ogd wrote:
if you are adding a VFO to a NC-40 I don't know why
Full band coverage would be nice.
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The Si5351 solution is very good.
Cost (from ebay, including shipping) estimate:
Si5351 board?? $4
Arduino??????????? $3
LCD??????????????????? $3
Encoder???????????? $1
Total?????????????????? $11
This includes all PCBs, just wires and 5V supply needed
And this is a very flexible elegant solution.?? You can have VFO
A/B, RIT, XIT, freq memories, passband
shifting, scaning, you name it.?? Of course, digital dial,
computer logging, CW decoding.? All you need is to do a little
coding or search it out on the internet.
On the other hand if you are adding a VFO to a NC-40 I don't know
why...? the NC-40 is amazingly stable and usable.
73,
Gary
WB6OGD
On 11/5/2019 12:52 PM, Mike M6MST
wrote:
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On Tue, Nov 5, 2019 at 11:52 AM, ajparent1/kb1gmx wrote:
FYI the 49er VFO design, the supplier apparently
stopped making it.
Are you talking about the Jack Purdum / Farrukh Zia board? If so
Jack mentioned in the SoftwareControlledHamRadio group that there
are lots of boards out there based on their design. Might be worth
looking into as Farrukh has gone somewhat MIA. I have one of these
kits and a 49er kit from eBay but if it will work with the 40A I
may just have to save the VFO board for that!
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Re: Do you have a favorite home brew short wave receiver to build with scouts?
Hi there,
If you’re willing to go to the FM broadcast band, a search for “The Radioshack Special” will turn up an interesting superregenerative circuit with ?one active device and a LM386. Easy circuit board and the performance is very good. It can be tweaked for the air and too.
de VK2HHS- Henrik
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On Tue, Nov 5, 2019 at 11:52 AM, ajparent1/kb1gmx wrote:
FYI the 49er VFO design, the supplier apparently stopped making it.
Are you talking about the Jack Purdum / Farrukh Zia board? If so Jack mentioned in the SoftwareControlledHamRadio group that there are lots of boards out there based on their design. Might be worth looking into as Farrukh has gone somewhat MIA. I have one of these kits and a 49er kit from eBay but if it will work with the 40A I may just have to save the VFO board for that!
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Arduino (uno or nano) , SI5351(many sources), 2 line by 16 char LCD(many many sources).
That will do it all very acceptable and the code to do that is out there.? Its good
to VHF.
The ad9850 is a very old part and has not enough bits to do higher frequencies
cleanly so it has spurs that show up be it digital out or analog.
FYI the 49er VFO design, the supplier apparently stopped making it.
Allison
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Hi
Differences among other things:
- A DDS is way faster than a synthesizer
- A DDS has, often, better frequency resolution
This being said if the choice is between an AD9850 and the Si5351A I will opt for the latter any time. NEC used an AD9850 in one of their HF receivers but only to max 5 MHz due to its poor performance. Later generation of DDSes are much better. I have worked a lot with both the AD9912 DDS and the Si5351A
Bo
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Why does that matter? It accomplishes the same thing if you use the digital
output of the 9850.
Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"
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----- Original Message ----- From: "Bo, OZ2M" <groups.io@...> To: < [email protected]> Sent: Tuesday, November 05, 2019 9:16 AM Subject: Re: [qrptech] DDS VFO! Hi Please not that the Si5351A is not a DDS. It is a synthesizer. BIG technological difference. Bo
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If you can find a 49er VFO you could use that.
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I don't like the QRP Labs VFO because the serial port is not available and it uses a parallels.
?
Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"
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----- Original Message -----
Sent: Tuesday, November 05, 2019 9:03 AM
Subject: Re: [qrptech] DDS VFO!
I have qrp-tech boards that need building, a DDS VFO would be great!
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The design is for either the QRP Labs SI 5351 module or the AD9850 Type I module.I am planning firmware for both.
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I use serial LCDs. I use Newhaven LCD modules. If I must use a parallel LCD I use a serial to parallel adapter.
The parallel LCDs tale too many pins.
?
Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"
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----- Original Message -----
Sent: Tuesday, November 05, 2019 7:49 AM
Subject: Re: [qrptech] DDS VFO!
Hi Bob,
That’s great. ?Are you using the Si5351 as the DDS? ?If you are that makes Things easier in that It can be used for both as the LO at the RF mixer and BFO for the IF mixer.
I’m interested to see what you come up with. :)
72,
Faisal VA3SFA
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On 2019-11-05 15:06, Bob Macklin wrote:
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I am deigning/building a DDS VFO for the NorCal40 and NorCal Sierra.
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The 49er DDS VFO could be used for both of these trancievers.
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Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"
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Hi
Please not that the Si5351A is not a DDS. It is a synthesizer. BIG technological difference.
Bo
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I have qrp-tech boards that need building, a DDS VFO would be great!
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Henrik Stenstrom
Bo, OZ2M