I¡¯m using the 78L08 and mv109. I may revert back to the capacitor and fine tuning pot. The real problem I had was stability, which I have now.
72/73 de Chas ai4ot
toggle quoted message
Show quoted text
On Apr 23, 2018, at 9:54 PM, John Backo <jabac@...> wrote:
In varactor tuning, your goal is to maximize the capacitance
variance from one end to the other.
Therefore, the real questions are two: what varactor is
being used, and what is the voltage range it is operating
under.
Note that most datasheets show varactor variance at
best linearity and maximum variance at a particular
voltage range, usually the lower end. So the first thing
is to determine the voltage range. Next, figure out a resistance
range that will exploit that. Usually, the voltage range is about
8v, and the full resistance range is about 10-15k.
It is a relatively simple matter to use 2 pots in series, one of
a higher value to set the frequency position, and one of a lower
range to fine tune. The only real advantage of a 10-turn pot is
to get better gross resolution, but a 10k and 1k regular linear
pot in series will accomplish about the same thing.
As to adding capacitance, that is what the varactor is doing.
It may be that more capacitance is needed to change the
base frequency of the VFO. Usually experimentation is
required, though a rough estimate can be made by figuring
out the total LC ratios. Where to add that capacitance
is another question: probably it will require some in the
main tank and some in the DC isolation of the varactor circuit.
For instance, I modified the VFO for the BITX20 v.3 as follows,
following the example of the BITX20A:
Q5 is a 2N3904; the two main VFO caps are 470 pF polystyrene.
The L4 coil is a T68-6 with 40t, measuring about 9 uH free-standing.
One of the secrets to a stable VFO was paralleling that coil with a
180 pF s.m capacitor. Main tuning is with a 365 pF variable cap,
in series with 2 parallel 220 pF caps, and then into the VFO circuit
of 5-45 pF range-finding cap in parallel with a 220 pF s.m. cap.
The basic tuning range is about 2.895 - 3.295 MHz. The original
test tuning range without the variable cap and a 220 pF in its place
was 2.95640 MHz to 2.965445 MHz (varying the 5-45 pF cap).
For fine tuning, I added a 78L08 regulator running to a 10-turn pot
with a 1K resistor to ground. That ran through a 200K resistor to
a MV2109 (to ground) and then to a 100 pF npo cap leading back
to the main oscillator. This gave a full range of about +/- 25 KHz for the fine
tuning.
So, in essence, the varicap mod added fine tuning. The main VFO
remained the principal tuning for the rig. It works well and is quite
stable.
The IF is 11.092 MHz, not the 10 MHz of the original BITX.
All of this information comes from my original pages of builder's
notes form Leonard's manual. I can publish the pages if you want,
but they are a bit hard to read if you didn't make them up originally.
The rig tunes from about 6.95 to 7.34 MHz.
Hope this helps.
john
AD5YE
|
Re: Teensy 3.5/3.6 upgrade for uBITX
Yep, every one is different and, man, are you gonna hate the Jackal board:
On Monday, April 23, 2018, 9:32:56 PM EDT, Kees T <windy10605@...> wrote:
Jack,
I agree that there are many people standing on Farhan's shoulders and he has certainly created/generated a huge interest in his uBIT-X design point..... key parameters being that the cost is being held low for a simple design to allow more people to try modifications if they want to ......AND he's allowing others to start small businesses and learn skills. I think the latter, in itself, is great.?
Message counts of ~2000 per month definitely indicate a huge interest.
My point was that there are many steps in the progression from the uBIT-X that arrived in the mailbox, TO one that has slight modifications, TO more comprehensive AGC hardware, audio amps, etc, TO SWR indications, 4 line displays, more keyer features,
TO DSP and other SW defined modes, RPi, Teensy 3.5/3.6, large touch screens, etc ......you get the idea. Many options. The point is that you can take the path and get off at any step. I personally want to go as far as I feel makes sense to me (staying with the Nano or an Arduino based derivative and basically "Keeping It Simple") with a result that I think I can reach, and a Transceiver I will/can use. Some of the guys that want to Hack-to-the- Max ....more power to them but the number of followers will drop off pretty quickly and I for one will become a (maybe) drooler, not a follower.? ?
73 Kees K5BCQ
|
Re: Teensy 3.5/3.6 upgrade for uBITX
One more item.............
I think it really supports the hobby when hams like Don, ND6T, provide a uBIT-X solution for something requiring a small board (like his AGC fix) and he also provides a schematic, use instructions, and quick layout which can be easily produced by someone with a piece of PC board and an X-Acto knife.? Hats off to you, Don.
For more complex small boards, there are plenty of board vendors out there who provide VERY inexpensive 2 layer boards and one of us can provide those boards (or the whole parts kit) at cost or close to cost. Just takes a little effort and time.
73 Kees K5BCQ
|
In varactor tuning, your goal is to maximize the capacitance
variance from one end to the other.
Therefore, the real questions are two: what varactor is
being used, and what is the voltage range it is operating
under.
Note that most datasheets show varactor variance at
best linearity and maximum variance at a particular
voltage range, usually the lower end. So the first thing
is to determine the voltage range. Next, figure out a resistance
range that will exploit that. Usually, the voltage range is about
8v, and the full resistance range is about 10-15k.
It is a relatively simple matter to use 2 pots in series, one of
a higher value to set the frequency position, and one of a lower
range to fine tune. The only real advantage of a 10-turn pot is
to get better gross resolution, but a 10k and 1k regular linear
pot in series will accomplish about the same thing.
As to adding capacitance, that is what the varactor is doing.
It may be that more capacitance is needed to change the
base frequency of the VFO. Usually experimentation is
required, though a rough estimate can be made by figuring
out the total LC ratios. Where to add that capacitance
is another question: probably it will require some in the
main tank and some in the DC isolation of the varactor circuit.
For instance, I modified the VFO for the BITX20 v.3 as follows,
following the example of the BITX20A:
Q5 is a 2N3904; the two main VFO caps are 470 pF polystyrene.
The L4 coil is a T68-6 with 40t, measuring about 9 uH free-standing.
One of the secrets to a stable VFO was paralleling that coil with a
180 pF s.m capacitor. Main tuning is with a 365 pF variable cap,
in series with 2 parallel 220 pF caps, and then into the VFO circuit
of 5-45 pF range-finding cap in parallel with a 220 pF s.m. cap.
The basic tuning range is about 2.895 - 3.295 MHz. The original
test tuning range without the variable cap and a 220 pF in its place
was 2.95640 MHz to 2.965445 MHz (varying the 5-45 pF cap).
For fine tuning, I added a 78L08 regulator running to a 10-turn pot
with a 1K resistor to ground. That ran through a 200K resistor to
a MV2109 (to ground) and then to a 100 pF npo cap leading back
to the main oscillator. This gave a full range of about +/- 25 KHz for the fine
tuning.
So, in essence, the varicap mod added fine tuning. The main VFO
remained the principal tuning for the rig. It works well and is quite
stable.
The IF is 11.092 MHz, not the 10 MHz of the original BITX.
All of this information comes from my original pages of builder's
notes form Leonard's manual. I can publish the pages if you want,
but they are a bit hard to read if you didn't make them up originally.
The rig tunes from about 6.95 to 7.34 MHz.
Hope this helps.
john
AD5YE
|
Re: Teensy 3.5/3.6 upgrade for uBITX
HI Jack,
Have you considered the Asus Tinker board?? Same form factor as
Rpi but even more capable.? Does cost more as well.? Quad core
1.8GHz, 2 Gb memory, Gb ethernet, 24 bit 192khz audio, GPIO, WiFi
& Bluetooth.
Cheers,
Will,
ZL1TAO
On 24/04/18 12:05, Jack Purdum via
Groups.Io wrote:
toggle quoted message
Show quoted text
I said almost the same thing a day or two ago...it has some
really nice features, like a 12-bit ADC (4096 instead of
1024). Another important plus is that it can be programmed and
run in the Arduino IDE.
Jack, W8TEE
In keeping in line with Farhan's $100 goal for the
Transceiver, I would seriously look at using the
"Protoneer" mentioned by some others. It has the
"Nano" form factor, is Arduino Zero based, runs at 3x
the Nano speed, has 8x the Nano flash memory, 16x the
Nano RAM, and has a DAC. Seems like that is a great
opportunity to sweep in some open source code like
that K3NG has for his keyer, other modes of operation,
and many, many, more features over time. 256KB of
flash memory is a LOT of available space. The
Protoneer is $10 and you can get a group together to
save on the $5 postage from NZ. I'm sure there are
plenty of firmware writers out there.
73 Kees K5BCQ
|
kenselectronics.com carries carbon elements. They are used but they are available. If you have any 1960-1980 Western Electric standard telephones, especially dial type, check to see if they have carbon elements. tim ab0wr On Mon, 23 Apr 2018 23:36:24 +0530 "Mvs Sarma" <mvssarma@...> wrote: In continuation, i suppose that except salvaged ones , we may not be
able to get carbon mics now a days.
Regards
MVS Sarma
On Mon, Apr 23, 2018 at 11:34 PM, Mvs Sarma <mvssarma@...>
wrote:
Simple . It works with a DC bias and resistance variation of carbon
granules packed in a mic convey the speech content.
Only diffiernce is that the bandwidth would be much less as against
electret or dynamic mics.
regards
sarma
vu3zmv
Regards
MVS Sarma
On Mon, Apr 23, 2018 at 11:28 PM, Arv Evans <arvid.evans@...>
wrote:
Lee
It will be interesting to see, and hear, how that T-32 carbon
button microphone
works with the BITX. It may need some attenuation because carbon
microphones
usually output a fairly high level signal. who knows...we could be
seeing a new
trend of using carbon microphones for their inherent frequency
limiting and high
output.
Arv K7HKL
_._
On Mon, Apr 23, 2018 at 10:32 AM, Lee <mr.olson@...> wrote:
The microphone is a Model T-32 made by Kellogg Company for
military communications. It was sometimes used with the English
T-1154 transmitter in WW2 Lancaster bombers. Yes, they were used
in many places after the war and one popular use was on a PA
system in railroad yards. Since I need 4 wires I am using a
Cobra/Midland CB style 4 pin plug and jack with the locking ring.
|
Re: KD8CEC 1.072 download
Thanks Ian for all your work you sure are packing a lot of features into that nano. I first modified the original firmware of Farhan¡¯s to fix a few issues I had with it and then I followed your development. I am using your version 1.06 and found it to be all that I needed in functionality. Thanks again for all your efforts.
toggle quoted message
Show quoted text
On Apr 23, 2018, at 20:56, Ian Lee < kd8cec@...> wrote: William
I use git for version control, but it seems to be difficult to trace history when the file name changes.
Instead, I will create a separate file to keep track of which files have changed each time I deploy.
All filenames are now cleaned up.
Since Version 1.070, there was work such as splitting and merging files to support various hardware.
I will publish Version 1.073 (Beta) within a day.
Thank you for testing the firmware.
Ian KD8CEC -- Best 73 KD8CEC / Ph.D ian lee kd8cec@...
(my blog)
|
Re: Teensy 3.5/3.6 upgrade for uBITX
Jack,
I agree that there are many people standing on Farhan's shoulders and he has certainly created/generated a huge interest in his uBIT-X design point..... key parameters being that the cost is being held low for a simple design to allow more people to try modifications if they want to ......AND he's allowing others to start small businesses and learn skills. I think the latter, in itself, is great.?
Message counts of ~2000 per month definitely indicate a huge interest.
My point was that there are many steps in the progression from the uBIT-X that arrived in the mailbox, TO one that has slight modifications, TO more comprehensive AGC hardware, audio amps, etc, TO SWR indications, 4 line displays, more keyer features,
TO DSP and other SW defined modes, RPi, Teensy 3.5/3.6, large touch screens, etc ......you get the idea. Many options. The point is that you can take the path and get off at any step. I personally want to go as far as I feel makes sense to me (staying with the Nano or an Arduino based derivative and basically "Keeping It Simple") with a result that I think I can reach, and a Transceiver I will/can use. Some of the guys that want to Hack-to-the- Max ....more power to them but the number of followers will drop off pretty quickly and I for one will become a (maybe) drooler, not a follower.? ?
73 Kees K5BCQ
|
Re: UBITX Assemly Wiki Page
#ubitx
Hi Bob,
Thanks for that great work to provide a clear diagram for the uBITX connections.
It highlights a point of possible confusion that will probably need to be clarified higher up the pay grades than we are :^))
Your diagram properly shows pin 1 of the 16-pin uBITX header to be not connected.
As indeed the uBITX PC board is physically made exactly that way.
But the PNG file schematics of the Raduino show pins 1 and 2 of that header connected together.
A check of a physical Raduino board confirms that connection.
And pin 2 provides the +12V line to the Raduino from the uBITX main board.
yet another But.... the PDF schematic files ubutxv3, ubitxv31, and ubitxv3-1 all show pin 1 as grounded.
No harm, no foul, as long as pin 1 remains physically "nc" on the uBITX main PCB.
But if those schematics portend a future revision which intends to ground that pin, that'll be an issue.
As an aside... if a revised main PCB were contemplated, using two adjacent pins for the +12 line would be a good idea from a reliability standpoint.
N5IB
|
Re: KD8CEC 1.072 download
William
I use git for version control, but it seems to be difficult to trace history when the file name changes.
Instead, I will create a separate file to keep track of which files have changed each time I deploy.
All filenames are now cleaned up.
Since Version 1.070, there was work such as splitting and merging files to support various hardware.
I will publish Version 1.073 (Beta) within a day.
Thank you for testing the firmware.
Ian KD8CEC
Ian... would you PLEASE consider writing the version number in the file name of the code?? That way different versions can be saved easily in the Arduino ISD.?
Dr.?William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it:
email:??bill@... ? On Apr 22, 2018, at 2:50 PM, Ian Lee < kd8cec@...> wrote: Rod, All
I am always thanking Rod.
And I'm sorry to interrupt Rod's work with too many changes in functionality.
1.072 will be tested and will be released as 1.073 Beta.
Several minor ones have been added.
Please wait for a day or two to download the code or firmware.?
Perhaps 1.07x will continue to be a Beta version.
Frequent formal firmware release seems to be inconvenient for some people, so I try to release it after various tests.
I think Version 1.061 is a stable version.?I know there is some nice firmware based on Version 1.061 and I will install it on my Spare uBITX.
Version 1.061 and later versions are also based on Version 1.061.
The Portable version and the various language versions are all excellent Firmware and I share code with them.
Please wait for a day or two?, I'll release version 1.073 beta after testing in various environments (including Linux).
Thank you
Ian KD8CEC
Best 73
KD8CEC / Ph.D ian lee
kd8cec@...
(my blog)
-- Best 73 KD8CEC / Ph.D ian lee kd8cec@...
(my blog)
|
Re: Low mic gain, was, show your mic
?
The ability to change course --- a mark of true character.
Cheers,
gordon
toggle quoted message
Show quoted text
Thank you Gordon.
?
Humbled.
?
Max K 4 O D S.
?
I've Never Lost the Wonder.
?
Antique Electronics Site:
?
?
?
Max, your web site is very impressive! ? great work!! ?
On Apr 22, 2018, at 23:12, Gordon Gibby <ggibby@...> wrote:
Multiple people have explained how to decrease the emitter resistor in the mic amplifier stage to incrase the gain.? ?I didn't think of that, so just built a 1-transistor preamp for it and was quite happy.? ? Also had to do that
for another transceiver I owned 30+ years ago.? ?Simple enough to do.? ??
?
Also be careful, the average power output measured by an analog scale is far far less than the peak if if you push the apparent average way up there....all you'll be doing is pushing the peaks into non-linear splattering.? ?
?
the older hams used to use oscilloscopes on their outputs so they could actually SEE when they were overmodulating.? ?Impressive amount of concern, I would say!? ? But I did get two of those type scopes for relatively cheap on ebay....use
them to show people what signals look like in license classes occasionally.
?
that's ham radio!
?it isn't meant to be easy
?
?
gordon
?
?
Whenever you wish to FUND that effort, you'll easily find people who will be willing to get on your payroll!!
?
If you look at that photo, there's a "clue" in that one terminal connects to the CASE.? ? And the legend that I always saw on the similar photo here:?
??
?is also a good giveaway.
?
This tutorial is another explanatory bit of information (about the first one that popped up in a google search for electret mic pinout)? ??
?
That's ham radio!
?
gordon
?
?
Interesting.? That picture has no indication as to which is positive and which is negative.? If I didn¡¯t already
know that the upper right connection was ground the picture would be useless.? I am probably offending some people but I¡¯m about fed up.? All of the correct information needs to be gathered in one place.? Call it a manual or whatever you want but ?someone
who knows needs to take the time and put forth the effort to put it together.? And then all the incorrect information needs to be removed from the web.?
?
Not a happy camper.
?
Max K 4 O D S.
?
I've Never Lost the Wonder.
?
Antique Electronics Site:
?
?
From:
[email protected] [mailto:[email protected]]
On Behalf Of Mvs Sarma
Sent: Sunday, April 22, 2018 1:57 PM
To: [email protected]
Subject: Re: [BITX20] Low mic gain, was, show your mic
?
please see the photo here.
?
The right side pin is for Ground.
if i recollect , a reverse polarity was also responding for voice but verey very lowand distorted.
?
On Sun, Apr 22, 2018 at 10:15 PM, MAX <max@...> wrote:
Hi
sarma.
?
I¡¯m sure I have the polarity correct.? Someone on this list posted a drawing showing how to identify the negative terminal and I wired according to it.? I think the
electret mic wouldn¡¯t work at all if polarity were reversed.? What is being powered is an ?F E T source follower.? ?I think I shouldn¡¯t have to raise my voice to get 5 watts output on 40 meters.
?
Regards.
?
Max K 4 O D S.
?
I've Never Lost the Wonder.
?
Antique Electronics Site:
?
?
From:
[email protected] [mailto:[email protected]]
On Behalf Of Mvs Sarma
Sent: Sunday, April 22, 2018 3:44 AM
To: [email protected]
Subject: Re: [BITX20] show your mic
?
?please check whether the mic body is connected to chasis ground.
i mean the positive bias voltage for mic should come on independent pin and NOT to the body pin of the eletret element.
In case you are using a dynamic mic, perhaps we need more gain and your need to shout appers logical.
regards
sarma
vu3zmv
?
On Sat, Apr 21, 2018 at 11:27 PM, MAX <max@...> wrote:
Speaking of mics, I have to raise my voice almost to the level of shouting to get 5 watts out on 40 meters.? Is
this normal or should I look for a problem?
?
Regards.
?
Max K 4 O D S.
?
I've Never Lost the Wonder.
?
Antique Electronics Site:
?
?
From:
[email protected] [mailto:[email protected]]
On Behalf Of Mvs Sarma
Sent: Saturday, April 21, 2018 7:17 AM
To: [email protected]
Subject: Re: [BITX20] show your mic
?
I had grabed a taperecorder mic with 3.5mm mono pin.
?replaced the cable with 2+shield.had a small pushed switchmounted and wired.
?repalced the 3.5mm momo pin to stereo pin. Here is a image of my mic.The pp9 battery helps to imagine the mic size.
regards
?sarma
?vu3zmv
?
?
|
Re: KD8CEC 1.072 download
Ian... would you PLEASE consider writing the version number in the file name of the code? ?That way different versions can be saved easily in the Arduino ISD.?
Dr.?William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it:
email:??bill@... ?
toggle quoted message
Show quoted text
On Apr 22, 2018, at 2:50 PM, Ian Lee < kd8cec@...> wrote: Rod, All
I am always thanking Rod.
And I'm sorry to interrupt Rod's work with too many changes in functionality.
1.072 will be tested and will be released as 1.073 Beta.
Several minor ones have been added.
Please wait for a day or two to download the code or firmware.?
Perhaps 1.07x will continue to be a Beta version.
Frequent formal firmware release seems to be inconvenient for some people, so I try to release it after various tests.
I think Version 1.061 is a stable version.?I know there is some nice firmware based on Version 1.061 and I will install it on my Spare uBITX.
Version 1.061 and later versions are also based on Version 1.061.
The Portable version and the various language versions are all excellent Firmware and I share code with them.
Please wait for a day or two?, I'll release version 1.073 beta after testing in various environments (including Linux).
Thank you
Ian KD8CEC -- Best 73 KD8CEC / Ph.D ian lee kd8cec@...
(my blog)
|
Re: Low mic gain, was, show your mic
Thank you Gordon. ? Humbled. ? Max K 4 O D S. ? I've Never Lost the Wonder. ? Antique Electronics Site: ? ?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Gordon Gibby
Sent: Sunday, April 22, 2018 10:23 PM
To: [email protected]
Subject: Re: [BITX20] Low mic gain, was, show your mic? Max, your web site is very impressive! ? great work!! ?
On Apr 22, 2018, at 23:12, Gordon Gibby <ggibby@...> wrote:
Multiple people have explained how to decrease the emitter resistor in the mic amplifier stage to incrase the gain.? ?I didn't think of that, so just built a 1-transistor preamp for it and was quite happy.? ? Also had to do that for another transceiver I owned 30+ years ago.? ?Simple enough to do.? ?? ? Also be careful, the average power output measured by an analog scale is far far less than the peak if if you push the apparent average way up there....all you'll be doing is pushing the peaks into non-linear splattering.? ? ? the older hams used to use oscilloscopes on their outputs so they could actually SEE when they were overmodulating.? ?Impressive amount of concern, I would say!? ? But I did get two of those type scopes for relatively cheap on ebay....use them to show people what signals look like in license classes occasionally. ? that's ham radio! ?it isn't meant to be easy ? ? gordon ? ?
Whenever you wish to FUND that effort, you'll easily find people who will be willing to get on your payroll!! ? If you look at that photo, there's a "clue" in that one terminal connects to the CASE.? ? And the legend that I always saw on the similar photo here:? ?? ?is also a good giveaway. ? This tutorial is another explanatory bit of information (about the first one that popped up in a google search for electret mic pinout)? ?? ? That's ham radio! ? gordon ? ?
Interesting.? That picture has no indication as to which is positive and which is negative.? If I didn¡¯t already know that the upper right connection was ground the picture would be useless.? I am probably offending some people but I¡¯m about fed up.? All of the correct information needs to be gathered in one place.? Call it a manual or whatever you want but ?someone who knows needs to take the time and put forth the effort to put it together.? And then all the incorrect information needs to be removed from the web.? ? Not a happy camper. ? Max K 4 O D S. ? I've Never Lost the Wonder. ? Antique Electronics Site: ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Mvs Sarma
Sent: Sunday, April 22, 2018 1:57 PM
To: [email protected]
Subject: Re: [BITX20] Low mic gain, was, show your mic ? please see the photo here.
?
The right side pin is for Ground. if i recollect , a reverse polarity was also responding for voice but verey very lowand distorted.
? On Sun, Apr 22, 2018 at 10:15 PM, MAX <max@...> wrote: Hi sarma. ? I¡¯m sure I have the polarity correct.? Someone on this list posted a drawing showing how to identify the negative terminal and I wired according to it.? I think the electret mic wouldn¡¯t work at all if polarity were reversed.? What is being powered is an ?F E T source follower.? ?I think I shouldn¡¯t have to raise my voice to get 5 watts output on 40 meters. ? Regards. ? Max K 4 O D S. ? I've Never Lost the Wonder. ? Antique Electronics Site: ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Mvs Sarma
Sent: Sunday, April 22, 2018 3:44 AM
To: [email protected]
Subject: Re: [BITX20] show your mic ? ?please check whether the mic body is connected to chasis ground. i mean the positive bias voltage for mic should come on independent pin and NOT to the body pin of the eletret element. In case you are using a dynamic mic, perhaps we need more gain and your need to shout appers logical. regards sarma vu3zmv
? On Sat, Apr 21, 2018 at 11:27 PM, MAX <max@...> wrote: Speaking of mics, I have to raise my voice almost to the level of shouting to get 5 watts out on 40 meters.? Is this normal or should I look for a problem? ? Regards. ? Max K 4 O D S. ? I've Never Lost the Wonder. ? Antique Electronics Site: ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Mvs Sarma
Sent: Saturday, April 21, 2018 7:17 AM
To: [email protected]
Subject: Re: [BITX20] show your mic ? I had grabed a taperecorder mic with 3.5mm mono pin.
?replaced the cable with 2+shield.had a small pushed switchmounted and wired.
?repalced the 3.5mm momo pin to stereo pin. Here is a image of my mic.The pp9 battery helps to imagine the mic size.
regards
?sarma
?vu3zmv
?
?
|
I wish to apologize for my statements on the list last night. I'm not
going to make excuses. I shouldn't have said what I said and I know it.
I'm likely to ask some stupid questions as I go along and I hope you all
will be patient with me.
Red in the face. 73.
Max. K 4 O DS.
P. S. I was not drinking.
I've Never Lost the Wonder.
Email: max@...
Vacuum Tube Site:
Transistor site:
Woodworking site:
Music site:
To subscribe to the fun with transistors group send an email to.
funwithtransistors-subscribe@...
To subscribe to the fun with tubes group send an email to,
funwithtubes-subscribe@...
To subscribe to the fun with wood group send a blank email to
funwithwood-subscribe@...
|
Yep, with a #2 on it.
Jack, W8TEE
On Monday, April 23, 2018, 8:13:21 PM EDT, Paul Schumacher via Groups.Io <wnpauls@...> wrote:
On Monday, April 23, 2018, 5:08:09 PM PDT, Jack Purdum via Groups.Io <jjpurdum@...> wrote:
Back when I was in school, I once wrote an essay with a manual graphite display generator.
Jack, W8TEE
On Monday, April 23, 2018, 7:01:26 PM EDT, William Cullison <wa8vih@...> wrote:
I made one from two carbon blocks, in a vertical configuration, with a dimpled area and a pencil sharpened at both ends.
On Mon, Apr 23, 2018 at 4:07 PM, Dexter N Muir <dexy@...> wrote: Carbon mics need a bit more bias current. Most can be revived by physical shock, breaking up clumps of granules packed by gravity in storage/disuse.
Challenge: the carbon mic that got me into electronics and eventually Ham Radio, some 60-odd years ago!
Take a (sorta fist-size to shoe-box) cardboard box lid.
Take 2 razor blades (single-sided are best)with wires attached.
Poke those blades up through the box-lid beside each other, (just) not touching. A twist of the insulated wires might help steady them.
Take a section of pencil-lead and balance that across the blade edges.
Connect up - you've got a mic!
73
Dex, ZL2DEX
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I put a SotaBeams DSP Audio Filter into my BITX40 and it works great. ?I have a 2nd one that I intend to use for my uBITX.
If you don't want to fuss with installing it in the rig you can get an enclosure for the filter and use it externally on different rigs.
These filters outperform any active audio filter I have ever used.?
There is also a small circuit board that is available from QRP Guys for the W0EB uBITX CW conditioning adaptor.
This helps to make the CW keying more reliable.?
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Re: Teensy 3.5/3.6 upgrade for uBITX
Jack
Well said. New tech license holders have a low cost incentive to get their general ticket and be able to join the community without fear of a steep investment.?
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On Apr 23, 2018, at 8:05 PM, Jack Purdum via Groups.Io < jjpurdum@...> wrote: I said almost the same thing a day or two ago...it has some really nice features, like a 12-bit ADC (4096 instead of 1024). Another important plus is that it can be programmed and run in the Arduino IDE.
Jack, W8TEE
On Monday, April 23, 2018, 7:01:53 PM EDT, Kees T < windy10605@...> wrote:
In keeping in line with Farhan's $100 goal for the Transceiver, I would seriously look at using the "Protoneer" mentioned by some others. It has the "Nano" form factor, is Arduino Zero based, runs at 3x the Nano speed, has 8x the Nano flash memory, 16x the Nano RAM, and has a DAC. Seems like that is a great opportunity to sweep in some open source code like that K3NG has for his keyer, other modes of operation, and many, many, more features over time. 256KB of flash memory is a LOT of available space. The Protoneer is $10 and you can get a group together to save on the $5 postage from NZ. I'm sure there are plenty of firmware writers out there.
73 Kees K5BCQ
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On Monday, April 23, 2018, 5:08:09 PM PDT, Jack Purdum via Groups.Io <jjpurdum@...> wrote:
Back when I was in school, I once wrote an essay with a manual graphite display generator.
Jack, W8TEE
On Monday, April 23, 2018, 7:01:26 PM EDT, William Cullison <wa8vih@...> wrote:
I made one from two carbon blocks, in a vertical configuration, with a dimpled area and a pencil sharpened at both ends.
On Mon, Apr 23, 2018 at 4:07 PM, Dexter N Muir <dexy@...> wrote: Carbon mics need a bit more bias current. Most can be revived by physical shock, breaking up clumps of granules packed by gravity in storage/disuse.
Challenge: the carbon mic that got me into electronics and eventually Ham Radio, some 60-odd years ago!
Take a (sorta fist-size to shoe-box) cardboard box lid.
Take 2 razor blades (single-sided are best)with wires attached.
Poke those blades up through the box-lid beside each other, (just) not touching. A twist of the insulated wires might help steady them.
Take a section of pencil-lead and balance that across the blade edges.
Connect up - you've got a mic!
73
Dex, ZL2DEX
|
Back when I was in school, I once wrote an essay with a manual graphite display generator.
Jack, W8TEE
On Monday, April 23, 2018, 7:01:26 PM EDT, William Cullison <wa8vih@...> wrote:
I made one from two carbon blocks, in a vertical configuration, with a dimpled area and a pencil sharpened at both ends.
On Mon, Apr 23, 2018 at 4:07 PM, Dexter N Muir <dexy@...> wrote: Carbon mics need a bit more bias current. Most can be revived by physical shock, breaking up clumps of granules packed by gravity in storage/disuse.
Challenge: the carbon mic that got me into electronics and eventually Ham Radio, some 60-odd years ago!
Take a (sorta fist-size to shoe-box) cardboard box lid.
Take 2 razor blades (single-sided are best)with wires attached.
Poke those blades up through the box-lid beside each other, (just) not touching. A twist of the insulated wires might help steady them.
Take a section of pencil-lead and balance that across the blade edges.
Connect up - you've got a mic!
73
Dex, ZL2DEX
|
Re: Teensy 3.5/3.6 upgrade for uBITX
I said almost the same thing a day or two ago...it has some really nice features, like a 12-bit ADC (4096 instead of 1024). Another important plus is that it can be programmed and run in the Arduino IDE.
Jack, W8TEE
On Monday, April 23, 2018, 7:01:53 PM EDT, Kees T <windy10605@...> wrote:
In keeping in line with Farhan's $100 goal for the Transceiver, I would seriously look at using the "Protoneer" mentioned by some others. It has the "Nano" form factor, is Arduino Zero based, runs at 3x the Nano speed, has 8x the Nano flash memory, 16x the Nano RAM, and has a DAC. Seems like that is a great opportunity to sweep in some open source code like that K3NG has for his keyer, other modes of operation, and many, many, more features over time. 256KB of flash memory is a LOT of available space. The Protoneer is $10 and you can get a group together to save on the $5 postage from NZ. I'm sure there are plenty of firmware writers out there.
73 Kees K5BCQ
|
Charles D. Smith
Skip Davis
K9HZ