More than a couple of decades ago I was working on a rural radio project
and I built something like this.
This can be used in Bitx for mic and amp with no switching voltages
required. T1 is also not needed as
we don't need electrical isolation.
?
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Re: W8TEE TFT/VFO Board from FDIM talk
Hi Kevin
I find that most stuff arrives within 10-15 days
73 de Charlie GI4FUE
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Kevin Gilot Sent: 01 June 2017 00:48 To: [email protected]Subject: Re: [BITX20] W8TEE TFT/VFO Board from FDIM talk Hi Charlie, What was the shipping time to get your stuff? I don't really want to wait a month or more. Thanks and 73, Kevin NZ1I Mystic, CT Sent from my iPhone --- This email has been checked for viruses by AVG.
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From NUTS and VOLTS
?
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Re: Conflicting information
Not the same as the as the 328. There is no 12 volt connector on the Raduino processor. There is on the R3 or 2560. The information you supplied refers to them. The 328 is powered from the 5 volt regulator on the Raduino board OR the USB connection. No automatic selection exists on? the Raduino. ? v/r Fred W4JLE ?
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From: [email protected] [mailto:[email protected]] On Behalf Of John Smith via Groups.Io
Sent: Wednesday, May 31, 2017 18:58
To: [email protected]
Subject: Re: [BITX20] Conflicting information ? Let's see if I can help. The Arduino site says this.- The Arduino/Genuino Uno board can be powered via the USB connection or with an external power supply. The power source is selected automatically. External (non-USB) power can come either from an AC-to-DC adapter (wall-wart) or battery. The adapter can be connected by plugging a 2.1mm center-positive plug into the board's power jack. Leads from a battery can be inserted in the GND and Vin pin headers of the POWER connector. The board can operate on an external supply from 6 to 20 volts. If supplied with less than 7V, however, the 5V pin may supply less than five volts and the board may become unstable. If using more than 12V, the voltage regulator may overheat and damage the board. The recommended range is 7 to 12 volts.
Automatically selected are the key words here. I had an UNO die because I plugged in the usb while it was already powered by DC jack.?This might have been a cheap chinese clone issue. I would advise against any DC power when connecting the Raduino for programming. The USB port has plenty of power for the Raduino.?
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Hi, I decided to do Bitx20, I use 10 MHz xtal, card is over and I get energy, whistling, what could be the problem. Nobin was wrapped with 8 rounds t50-2, thank you. 
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Hello, I decided to do bitx20, I used 10 MHz xtal, I ran out of card and got energy, I hear whistling sound, what could be the problem. The trailers were wrapped with 8 rounds t50-2, thank you.
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Re: Conflicting information
It should not be done.? Putting two sources in parallel that may be at a different potential is never a good idea. While it may ?or may not hurt the BITX, it could play hell with the computer USB port. ? v/r Fred W4JLE ?
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From: [email protected] [mailto:[email protected]] On Behalf Of John P
Sent: Wednesday, May 31, 2017 17:54
To: [email protected]
Subject: Re: [BITX20] Conflicting information ? Thanks! Powering something from 2 sources simultaneously scares me as I already
blew up an expensive gimmick that way!
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Re: D7/C130 connected incorrectly
Hmmm... OK. ?Well, thank you for at least replying to my post.
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Re: Spurious RF at beginning of transmission
Same transformers are available from China, 10 for 3$ with free shipping
or so.
Some sellers with 2/5 pcs even cheaper.
Raj
At 01/06/2017, you wrote:
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Possible.? Wants $1.39 +
$3.15 for shipping, so the transformer is kind of painful.
Especially with a thousand or more rigs spread around the world now.
I'd probably advise that most just live with the pop and use Allard's
scheme for CW
Those that aren't interested in CW can use your easily scrounged 0.1uF
fix.
?
On Wed, May 31, 2017 at 09:39 pm, Raj vu2zap wrote:
- We could put an audio isolation transformer between the mic/preamp
stages and the mixer.
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Re: Spurious RF at beginning of transmission
Possible. ?Wants $1.39 + $3.15 for shipping, so the transformer is kind of painful.
Especially with a thousand or more rigs spread around the world now.
I'd probably advise that most just live with the pop and use Allard's scheme for CW
Those that aren't interested in CW can use your easily scrounged 0.1uF fix.
?
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On Wed, May 31, 2017 at 09:39 pm, Raj vu2zap wrote:
We could put an audio isolation transformer between the mic/preamp stages and the mixer.
?
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Thanks for the part number.
I am using the Bitx40
schematic from his Bitx40 web page, and it still shows the
1N4148s....
I am right now comparing the
schematic to the Bitx40 board I have and marking up the
schematic so it matches my board.
David Martin - - Mountain
Home, Ar.
-----------------------------------------
Everybody complains about CO2, but nobody complains about all
the trees cut down to build Highways and Cities.
Recycle, Reuse, Re-purpose, Repair
On 5/31/2017 23:40, Mvs Sarma wrote:
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it is? BAT54S in sot23 package.
?It replaces the two 4148 diodes used for de-modulator.
?? Once it is mounted the balancing trim pot can be
bypassed. also one capacitor could be removed.
?please check the concerned sch, ifyou had downloaded earlier.
?Appears F arhan has replaced that schematic
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it is? BAT54S in sot23 package.
?It replaces the two 4148 diodes used for de-modulator. ?? Once it is mounted the balancing trim pot can be bypassed. also one capacitor could be removed. ?please check the concerned sch, ifyou had downloaded earlier. ?Appears F arhan has replaced that schematic
On Thu, Jun 1, 2017 at 4:29 AM, davemrtn <davemrtn@...> wrote:
What is the part number for
the dual diode package "D20" on the Bitx-40 V3 board ?
--
David Martin -
- Mountain Home, Ar.
-----------------------------------------
Everybody complains about CO2, but nobody complains about all
the trees cut down to build Highways and Cities.
Recycle, Reuse, Re-purpose, Repair
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Re: Spurious RF at beginning of transmission
Jerry,
We could put an audio isolation transformer between the mic/preamp stages
and the mixer.
The mixer side will need to be ground isolated then Allards CW will work
and probably the carrier leak on SSB will be minimum.
Some thing like these transformers:
I have some isolation transformers, will experiment when I get back
to town next week.
Cheers
Raj
At 01/06/2017, you wrote:
A very nice $0.01 solution.
Except it kills how Allard is doing CW.
He unbalances the carrier by putting 5v into a 10k resistor that goes to
the top of C107.
Maybe fix this PTT pop somehow in microphone preamp so we can continue to
use Allard's CW method?
Could transmit CW like Farhan is doing it on the uBitx:? Move the
VFO to the transmit freq and unbalance the first ring mixer.? Those
three mixer ports got stirred up considerably on the uBitx, though it is
otherwise the same mixer as on the Bitx40.? Is there a some simple
way to do this without a significant hardware hack to the existing Bitx40
boards?
......snip........
Jerry, KE7ER
On Wed, May 31, 2017 at 08:13 pm, Raj vu2zap wrote:
- See my solution:
-
/g/BITX20/topic/ptt_pop_hack/4460108?p=,,,20,0,0,0::Relevance,,PTT+pop+raj,20,2,0,4460108
?
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What is the part number for
the dual diode package "D20" on the Bitx-40 V3 board ?
--
David Martin -
- Mountain Home, Ar.
-----------------------------------------
Everybody complains about CO2, but nobody complains about all
the trees cut down to build Highways and Cities.
Recycle, Reuse, Re-purpose, Repair
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Re: Spurious RF at beginning of transmission
A very nice $0.01 solution.
Except it kills how Allard is doing CW.
He unbalances the carrier by putting 5v into a 10k resistor that goes to the top of C107.
Maybe fix this PTT pop somehow in microphone preamp so we can continue to use Allard's CW method??
Could transmit CW like Farhan is doing it on the uBitx: ?Move the VFO to the transmit freq and unbalance the first ring mixer. ?Those three mixer ports got stirred up considerably on the uBitx, though it is otherwise the same mixer as on the Bitx40. ?Is there a some simple way to do this without a significant hardware hack to the existing Bitx40 boards?
Don Cantrell was injecting RF at the transmit freq from a spare Si5351 output, ?Could key it by writing to an Si5351 register, so could be done with just a resistor. ?But this method does not offer an easy method for key shaping, whereas the mixer unbalance schemes used by Allard and Farhan do. ?With Allard's it's C107 that gives key shaping, on Farhan's uBitx it's C1. ?Though I think the uBitx's C1 may need to be considerably larger (maybe 1uF, though I'm not sure how the BiDi amp affects this) to give appropriate rise and fall times to the keying envelope. ?Allard's original 47k resistor was probably about right for the 0.1uF C107, the move to 10k makes the edges a bit fast, but we could go back to 47k if the BFO is driven from CLK0 and thus can be centered in the crystal filter passband. ?Keying envelopes may not matter much for a one off rig at 5W, but for wide distribution and the inevitable use with QRO amps, I'd want clean CW key shaping.
Jerry, KE7ER
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On Wed, May 31, 2017 at 08:13 pm, Raj vu2zap wrote:
See my solution:
/g/BITX20/topic/ptt_pop_hack/4460108?p=,,,20,0,0,0::Relevance,,PTT+pop+raj,20,2,0,4460108
?
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Re: Conflicting information
John, The Raduino is normally powered via 12 volts fed through the 5 volt regulator in operation. When programming it is powered via the USB cable. In short, turn the radio off, plug in the usb and program. ? v/r Fred W4JLE
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From: [email protected] [mailto:[email protected]] On Behalf Of John P
Sent: Wednesday, May 31, 2017 17:45
To: [email protected]
Subject: [BITX20] Conflicting information ? Hi Everyone! As you can see I just joined this group this morning at the recommendation of a friend.
I'm just finishing up a BITX40, which is the first think I've done in Ham Radio in the last 20 years
or so.
I found 2 articles on here?describing how to upload software into the Raduino; one by Pat
Griffin in the messages list, and one in the WIKI section. Pat's article says the Raduino
should be powered off when connecting it to the computer via the USB port (which I
tend to think is correct), while the WIKI article says the BITX should be powered on. Hopefully
someone with the capability to do so, can correct whichever one is wrong.
--
John - WA2FZW
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Re: Spurious RF at beginning of transmission
See my solution: /g/BITX20/topic/ptt_pop_hack/4460108?p=,,,20,0,0,0::Relevance,,PTT+pop+raj,20,2,0,4460108 Raj
At 01/06/2017, you wrote: Ashhar Farhan VU2ESE's BITX40 is an amazing QRP SSB Radio and has set an unbelievable price-performance point. And many folks are adding new bells/whistles every day (like Allard and Jack). I've been working with a friend of mine, Willy W1LY, and his BITX40. Willy had installed the version 1.13 software from Allard and the HW modifications needed for CW. We have both noticed some interesting RF behavior when the radio first enters TX, even when on LSB (just PTT, with no audio).
After some investigation we are reasonably certain that the burst of RF is coming directly through the balanced mixer which is unbalanced for about 60 mS due to the microphone amplifier stage being switched on for transmit. If one starts with the radio in RX, then C124, the 47uF cap in the mic amplifier is sitting at zero volts. When the radio goes into TX, that cap has to charge up via R127 -- which takes a LONG time.
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Re: D7/C130 connected incorrectly
The current configuration works fine.
The D7 protects the board from accidental polarity reversal. I would recommend replacing it with a 1A diode.
You can put a 1N4148 across the relay.
Raj, vu2zap
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At 31/05/2017, you wrote:
High voltage spikes could result went the PPT control line is opened. Also D7 will be damaged if the 12v power leads are accidentally reversed.
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Re: Spurious RF at beginning of transmission
Message 22961 proposed a solution to this. I implemented it thinking it was a solution to the audio pop and so unimplemented it when it didnt solve for problem. Unfortunately i didnt test to see if it solved the carrier burst issue.
Regards?
Simon VK3ELH
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Dale,
One of my Nano clones has a poor USB socket and the plug would only go in about ? ways.? Reference /g/BITX20/topic/if_raduino_programming_cable/4334102?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,40,4334102 ?I used a piece of 1/16¡± (1.5mm) music wire and ground (filed) one end to a needlepoint. Then bend the needle end 90 degrees about 3/16¡± (8mm). I now had a ¡°L¡± shaped hook that I could gently reach into the socket and move the tiny metal finger that was preventing the plug from being inserted all the way. Took several attempts of bending it back and forth but the metal finger finally broke off and fell out of the socket. Attached pic shows a rectangular ¡°hole¡± where the metal finger had been. ??This may explain some of the difficulty some members are having with USB cables.
Paul KL7FLR
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Raj vu2zap
Charlie Morrison
K7IOW
