Arduino USB cable extension ???
Hello.
Does an OM use a USB cable that would connect the Raduino to the back of the case ?
This is to avoid removing the cover at each update.
I think I read a post on the subject but I can not find.
Thank you and 73.
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Re: Carrier Null revisited
Good Afternoon, All.
A little help understanding here would be appreciated.
A given TX on AM or SSB would have an amplitude envelope proportional to the modulated audio signal, right?
What is the amplitude of that signal if there is no audio excitation?? I wouldn't expect zero.? I would key a shorted mic and there would be some carrier with no amplitude modulation.
If we were looking at the math, the output of the TX would be something like, A*sin f + C, where C would be the signal with no one talking into the mic, right?
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Re: Carrier Null revisited
Might be easier to work on the bitx40 than you think.
Have you tried?
I find the 1206 C's and R's much easier to work with than through-hole parts, using two soldering irons to remove them.
On that sot23 diode, heat up the single pin on one side, solder wick away excess solder, then pry it up with an xacto knife.
Then do the same with the other two pins.
Replace with axial lead 1n4148's and a pot of your choice as shown in the schematic.
You do need good light, good magnification, and no coffee.
Or perhaps a young assistant who might have a vague interest in becoming a radio amateur.
At $59, this is all way easier and cheaper than the typical SSB kit.
Was developed in part as a way to encourage hams to get out a soldering iron and hack at it.
Jerryd
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On Tue, Oct 31, 2017 at 07:16 am, Grayson Evans wrote:
The problem with this board is if there is something wrong there is no way I can repair or modify it. Ultra small surface mount is not my idea of fun.
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Re: Carrier Null revisited
I ran some math on your measurements, assuming 5 W maximum output and your carrier would be right near 30 db down. for comparison, an older model ICOM-28 was specified to have at least 40 db carrier suppression, so for an inexpensive home brew rig this isn't terrible. Perhaps with a matched set that could be nulled you could do better if you needed. gordon ________________________________________ From: [email protected] < [email protected]> on behalf of Grayson Evans <wa4gvm@...> Sent: Tuesday, October 31, 2017 10:15 AM To: [email protected]Subject: Re: [BITX20] Carrier Null revisited OK will check. I checked the carrier output (no mic and the PTT grounded). I get about 1.5V p-p into a dummy load. That equates to about 5 mW. Not much, but enough to make a CW contact by keying the PTT line! Maybe Ill convert it to CW! The problem with this board is if there is something wrong there is no way I can repair or modify it. Ultra small surface mount is not my idea of fun. Grayson On Oct 30, 2017, at 10:57 PM, Raj vu2zap <rajendrakumargg@...> wrote:
Grayson,
Measure the DC voltage in both RX and TX modes across C107. It should be zeroif not you will have a carrier
leak.
You complaint that external modulation sounds bad could be something related to the above or simply that
in close proximity you will hear mains hum modulating a carrier. Try a QSO with some near by ham and see.
Raj
At 31/10/2017, you wrote:
So i heard about the diode/pot replacement, but I can?€?t even find the dual diode on the board or where R105 used to be.
I am keying the transmitter into a dummy load and monitoring with a scope. I am also listening on a Collins receiver with its antenna disconnected. The carrier seems way to high but I didn?€?t write down the exact voltage on the scope. The receiver across the room shows an S9 with no antenna, but the metal enclosure on the BiTX is open, so a lot of signal escaping.
Also, the audio sounds terrible from the little crystal mic. I injected a 20mV 400 cycle tone into the mic input just to see if it was the mic. The tone also sounds terrible. Sounds like the tone is modulated with another low frequency (I checked DC supply and its clean).
I was going to do some signal following with the scope, but I have a heck of a time trying to identify where the components are on the board. In another post I asked if anyone has a board layout drawing. There is one somewhere but not on Farhans site.
Thanks
KJ7UM Grayson
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Re: Instructions for using the Raduino v1.26 (PE1NWL) in French.
#bitx40help
Hi Sarma,
thanks for the suggestion, I will consider your idea for auto band
switching in raduino v2.
However even if we offer auto band switching, I believe most ops would
still want to have an additional manual switch or button. Because it
allows for quick band switching without having to turn the dial all the
way up or down just to switch bands.
73 Allard PE1NWL
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On Tue, October 31, 2017 15:06, Mvs Sarma wrote: hi Allard,
I suppose that following procedure could be implementable for a possible
2
band working.
Initially the VFO would start with 40m band with LSB and 10/12MHz BFO
switchable with fine adjustment.
As you go to end of the band , it could perhaps aumatically switch over
to
20m with usb , and same selectable VFO , BUT now th LPF can be switched by
a relay.
There might not be any need for any extra button for band change.
On e way down from 20m
if some one continues to reduce below 14.00 , it could revert to 7MHz
(40m), obviously lsb and filter relay released for 40m lpf.
Thuis is wild imagination , I am nott from Software at all.Kindly study
the possibility.
regards
sarma
vu3zmv
regards
Sarma
On Tue, Oct 31, 2017 at 7:04 PM, F1NQP JanJack <f1nqp@...> wrote:
On Tue, Oct 31, 2017 at 06:19 am, Allard PE1NWL wrote:
However these are now obsolete as the si5351 library is no longer used
by
the raduino sketch. So you may want to remove this section.
Hello Allard.
No library is to install?
I can delete everything related to the installation of libraries?
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Re: Carrier Null revisited
OK will check.
I checked the carrier output (no mic and the PTT grounded). I get about 1.5V p-p into a dummy load.
That equates to about 5 mW. Not much, but enough to make a CW contact by keying the PTT line!
Maybe Ill convert it to CW!
The problem with this board is if there is something wrong there is no way I can repair or modify it. Ultra small surface mount is not my idea of fun.
Grayson
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On Oct 30, 2017, at 10:57 PM, Raj vu2zap <rajendrakumargg@...> wrote:
Grayson,
Measure the DC voltage in both RX and TX modes across C107. It should be zeroif not you will have a carrier
leak.
You complaint that external modulation sounds bad could be something related to the above or simply that
in close proximity you will hear mains hum modulating a carrier. Try a QSO with some near by ham and see.
Raj
At 31/10/2017, you wrote:
So i heard about the diode/pot replacement, but I can?€?t even find the dual diode on the board or where R105 used to be.
I am keying the transmitter into a dummy load and monitoring with a scope. I am also listening on a Collins receiver with its antenna disconnected. The carrier seems way to high but I didn?€?t write down the exact voltage on the scope. The receiver across the room shows an S9 with no antenna, but the metal enclosure on the BiTX is open, so a lot of signal escaping.
Also, the audio sounds terrible from the little crystal mic. I injected a 20mV 400 cycle tone into the mic input just to see if it was the mic. The tone also sounds terrible. Sounds like the tone is modulated with another low frequency (I checked DC supply and its clean).
I was going to do some signal following with the scope, but I have a heck of a time trying to identify where the components are on the board. In another post I asked if anyone has a board layout drawing. There is one somewhere but not on Farhans site.
Thanks
KJ7UM Grayson
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Re: Instructions for using the Raduino v1.26 (PE1NWL) in French.
#bitx40help
hi Allard,
?I suppose that following procedure could be implementable for a possible 2 band working. ?Initially the VFO would start with 40m band with LSB and 10/12MHz BFO switchable with fine adjustment. ?As you go to end of the band , it could perhaps aumatically switch over to 20m with usb , and same selectable VFO , BUT now th LPF can be switched by a relay. There might not be any need for any extra button for band change. On e way down from 20m ?if some one continues to reduce below 14.00 , it could revert to 7MHz (40m), obviously lsb and? filter relay released for 40m? lpf. ?Thuis is wild imagination , I am nott from Software at all.Kindly study the possibility.
On Tue, Oct 31, 2017 at 7:04 PM, F1NQP JanJack <f1nqp@...> wrote: On Tue, Oct 31, 2017 at 06:19 am, Allard PE1NWL wrote:
However these are now obsolete as the si5351 library is no longer used by
the raduino sketch. So you may want to remove this section.
Hello Allard.
No library is to install?
I can delete everything related to the installation of libraries?
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Re: Instructions for using the Raduino v1.26 (PE1NWL) in French.
#bitx40help
OK i modify my article accordingly.
Thanks again Alllard.
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Re: Instructions for using the Raduino v1.26 (PE1NWL) in French.
#bitx40help
Since v1.20, Jerry's minimal si5351 routines are included in the sketch
code. Hence we don't need to install the si5351 library anymore.
Note that the sketch still requires some other libraries (wire, eeprom,
liquidcrystal) but these are already included in the IDE, so you won't
need to manually download and install them.
73 Allard PE1NWL
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On Tue, October 31, 2017 14:34, F1NQP JanJack wrote: On Tue, Oct 31, 2017 at 06:19 am, Allard PE1NWL wrote:
However these are now obsolete as the si5351 library is no longer used
by
the raduino sketch. So you may want to remove this section.
Hello Allard.
No library is to install?
I can delete everything related to the installation of libraries?
|
Re: Instructions for using the Raduino v1.26 (PE1NWL) in French.
#bitx40help
On Tue, Oct 31, 2017 at 06:19 am, Allard PE1NWL wrote:
However these are now obsolete as the si5351 library is no longer used by
the raduino sketch. So you may want to remove this section.
Hello Allard. No library is to install?
I can delete everything related to the installation of libraries?
|
Re: Instructions for using the Raduino v1.26 (PE1NWL) in French.
#bitx40help
Dear Jean-Jacques,
thanks for the French translations.
I noticed that on this page there are still instructions for installing
the si5351 library:
Installez les biblioth¨¨ques depuis le programme Arduino:
Il va falloir maintenant installer les biblioth¨¨ques qui vont servir au
SI5351.
However these are now obsolete as the si5351 library is no longer used by
the raduino sketch. So you may want to remove this section.
73 Allard PE1NWL
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On Tue, October 31, 2017 13:55, F1NQP JanJack wrote: Hello.
You will find the instructions for using the Raduino v1.26 from PE1NWL,
translated into French on my website.
(
)
So I have not yet started editing my Bitx40, but at least I have a notice
in French ;-)
73 to all.
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Instructions for using the Raduino v1.26 (PE1NWL) in French.
#bitx40help
Hello.
You will find the instructions for using the Raduino v1.26 from PE1NWL, translated into French on my website.
So I have not yet started editing my Bitx40, but at least I have a notice in French ;-)
73 to all.
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On Mon, Oct 30, 2017 at 08:07 am, Allard PE1NWL wrote:
While you're waiting for the delivery of the 10T pot, you can already
start with the rest of the modifications.
Although highly recommended, the 10T pot is not strictly required - the
software will still work OK with the standard supplied pot.
Thank you Allard.
I'll come here post some pictures :-)
Good day to all.
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Re: Carrier Null revisited
?e are duiscuissing around BFO carrier leak. As has been explained well that a chip dual diodes are internally balancedenough. Even if suppose one uses discrete diodes,one could minimize but not eliminate carrier leak. It is analogeous to? non exuixtance of 0 and Infinity.
The nulled carrier to one's expectation gets amplified at PA as correctly suggested by Asher Farhan.? but I suppose that we need to make relative measurements. ? sarma
?vu3zmv
?
On Tue, Oct 31, 2017 at 8:27 AM, Raj vu2zap <rajendrakumargg@...> wrote: Grayson,
Measure the DC voltage in both RX and TX modes across C107. It should be zeroif not you will have a carrier
leak.
You complaint that external modulation sounds bad could be something related to the above or simply that
in close proximity you will hear mains hum modulating a carrier. Try a QSO with some near by ham and see.
Raj
At 31/10/2017, you wrote:
>So i heard about the diode/pot replacement, but I can¡¯t even find the dual diode on the board or where R105 used to be.
>
>I am keying the transmitter into a dummy load and monitoring with a scope.? ?I am also listening on a Collins receiver with its antenna disconnected.? The carrier seems way to high but I didn¡¯t write down the exact voltage on the scope.? The receiver across the room shows an S9 with no antenna, but the metal enclosure on the BiTX is open, so a lot of signal escaping.
>
>Also, the audio sounds terrible from the little crystal mic.? I injected a 20mV 400 cycle tone into the mic input just to see if it was the mic.? The tone also sounds terrible.? Sounds like the tone is modulated with another low frequency (I checked DC supply and its clean).
>
>I was going to do some signal following with the scope, but I have a heck of a time trying to identify where the components are on the board.? In another post I asked if anyone has a board layout drawing. There is one somewhere but not on Farhans site.
>
>Thanks
>KJ7UM Grayson
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Re: Carrier Null revisited
Grayson,
Measure the DC voltage in both RX and TX modes across C107. It should be zeroif not you will have a carrier
leak.
You complaint that external modulation sounds bad could be something related to the above or simply that
in close proximity you will hear mains hum modulating a carrier. Try a QSO with some near by ham and see.
Raj
toggle quoted message
Show quoted text
At 31/10/2017, you wrote: So i heard about the diode/pot replacement, but I can?€?t even find the dual diode on the board or where R105 used to be.
I am keying the transmitter into a dummy load and monitoring with a scope. I am also listening on a Collins receiver with its antenna disconnected. The carrier seems way to high but I didn?€?t write down the exact voltage on the scope. The receiver across the room shows an S9 with no antenna, but the metal enclosure on the BiTX is open, so a lot of signal escaping.
Also, the audio sounds terrible from the little crystal mic. I injected a 20mV 400 cycle tone into the mic input just to see if it was the mic. The tone also sounds terrible. Sounds like the tone is modulated with another low frequency (I checked DC supply and its clean).
I was going to do some signal following with the scope, but I have a heck of a time trying to identify where the components are on the board. In another post I asked if anyone has a board layout drawing. There is one somewhere but not on Farhans site.
Thanks
KJ7UM Grayson
|
Hi All, I have been thinking of moving the BITX40 to 144 MHz. 144 MHz is a common tunable IF for Microwave Hams. The FT717 is very popular as a tunable IF, however some are still using IC202 and FT290. ? The 144 MHz version of the BITX40 would be a good replacement for the aging IC202 and FT290. ? Comments please. ? 73 Gary vk2kyp ? ? ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Ashhar Farhan
Sent: Tuesday, October 31, 2017 02:58
To: [email protected]
Subject: Re: [BITX20] Raduino as NBFM TX? arv, the original intend was to get a 'toy' FM broadcast transmitter going to provide simultaneous translations for an international conference of organic farmers. the crystal swing wasn't enough to produce a decent audio. then i reprogrammed it work for 145 MHz and it sounded quite reasonable. i must look up the phase modulation schemes in the literature and try them out. ? On Mon, Oct 30, 2017 at 9:18 PM, Arv Evans <arvid.evans@...> wrote: Farhan
Phase modulation was popular with commercial VHF radios in the 1950's era.? Maybe it works best with high impedance resonance?? If that is the case then the modulated stage could be a JFET or MOSFET.? Obviously some room for ? On Mon, Oct 30, 2017 at 9:44 AM, Ashhar Farhan <farhanbox@...> wrote: Arv, I could never get the indirect modulation to work. Perhaps you could play with it. ? On 30 Oct 2017 8:47 pm, "Arv Evans" <arvid.evans@...> wrote: Hans & Farhan
There is always reactance or phase modulation. ? On Mon, Oct 30, 2017 at 6:12 AM, Hans Summers <hans.summers@...> wrote: Hi Farhan Great project! I am surprised that it works, though! I thought the PLL settling time of the Si5351A would be too slow to allow NBFM by applying FM to the reference crystal.? I once tried very quick frequency change commands issued by firmware to the Si5351A but it could not cleanly keep up with more than a few hundred Hz. Let me know though if you find differently! ? On Sun, Oct 29, 2017 at 8:26 PM, Ashhar Farhan <farhanbox@...> wrote: yeah, ? i am trying to figure out the simplest way to get on 2m nbfm. not sure which way to go. ? On Sun, Oct 29, 2017 at 10:48 PM, William R Meara <bill.meara@...> wrote: But remember the admonition of the great Cliff Stoll:? "I guess today's experimenters build things in software, without ever touching a soldering iron. The hocus pocus is inside the program.? It's cleaner this way -- nothing to burn or zap, and you don't need a voltmeter... What happened to home-brewed and breadboarded circuitry? Where's the joy of mechanics and electricity, the creation of real things?? Who are the tinkerers with a lust for electronics? "? ?From "Silicon Snake Oil"? 1995.?? ? On Sun, Oct 29, 2017 at 1:09 PM, Ashhar Farhan <farhanbox@...> wrote: I was thinking that it could be entirely done in software. The audio can be coupled to an analog input of the arduino. The arduino can sample the analog input and accordingly shift the PLL oscillator. I must try that out too.? ? On Sun, Oct 29, 2017 at 6:29 PM, Pete Juliano <jessystems@...> wrote: Very nice. It only gets better. Maybe when 10 Meters comes back there may be an interest in NBFM in gear other than VHF and UHF. Sent: Saturday, October 28, 2017 11:48 PM Subject: Raduino as NBFM TX By adding a couple of components, the Raduino can become a very stable NBFM transmitter. I just blogged my build : This will work equally well with the qrp-labs Si5351 too. ? ? ? ? ? ? ?
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Re: Carrier Null revisited
Grayson KJ7UM wrote... How the heck is a builder supposed to fix carrier
null with no null, AND no way to adjust the BFO
frequency. Did cost reduction make this board
useless for adjustments? I don't think it's a design problem. You are suspecting the diodes. You might be right, but perhaps it would be worth looking at the connections for T4. Perhaps there is a bad solder connection on one of the windings. They should all "work out of the box" but I always figure part of the fun if you are one of the lucky few that have to do some troubleshooting - hi! -- 73 Keith VE7GDH
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Re: Carrier Null revisited
grossly testing my rig tonight (with a receiver right near it) I can hear some carrier also but it doesn't move the SWR or power needle at all on a cheap SWR meter, and whistling I can get several watts (like 60% upscale movement of the meter). So the carrier is many dB below the SSB, just maybe not oodles of dB lower. both of my 2 bitx40's have the combined diode with no adjustment. ________________________________________ From: [email protected] < [email protected]> on behalf of Keith VE7GDH <ve7gdh@...> Sent: Monday, October 30, 2017 9:05 PM To: [email protected]Subject: Re: [BITX20] Carrier Null revisited Grayson KJ7UM wrote... > I can¡¯t even find the dual diode on the board or > where R105 used to be. See the hand drawing that I posted. I marked them D15 / D16 like in the drawing, even though it is a dual-diode in one package. I think Dexter said it is labeled D20 now. I didn't pop the lid to look. I wouldn't be too hasty in removing the diodes though before checking it out a bit further. -- 73 Keith VE7GDH
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Re: Carrier Null revisited
Grayson KJ7UM wrote... I can¡¯t even find the dual diode on the board or
where R105 used to be. See the hand drawing that I posted. I marked them D15 / D16 like in the drawing, even though it is a dual-diode in one package. I think Dexter said it is labeled D20 now. I didn't pop the lid to look. I wouldn't be too hasty in removing the diodes though before checking it out a bit further. -- 73 Keith VE7GDH
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Re: Carrier Null revisited
The dual-diode is labelled D20 on the board, and it's inside the triangle formed by the pads for a large version of the Pot - which is depicted. D20 is obscuring the wiper pad for the smaller (standard) version of the pot, which is the same style as R136 the Tx drive pot. The whole shebang sits next to the toroid (that looks like a 6-pin IC) bottom-left on the Wire Up picture on hfsigs site.
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F1NQP JanJack
Arvo W0VRA
Allard PE1NWL
Raj vu2zap