Jack,
a couple of thoughts,
1) put your design on oshpark as a shared project. Others could then
order (in multiples of three) at a reasonable price.
2) contact Hans Summer G0UPL ( I seem to recall he is a member of
this group) who runs he may have some good
ideas on how to better do what you are trying to do.
Either way, your commitment to providing these boards at a
reasonable cost is commendable
Cheers, Graham ve3gtc
On 2017-05-31 19:30, Jack Purdum via
Groups.Io wrote:
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All:
I
just spent an hour at the post office while they processed
each foreign order. Last night I spent another several hours
filling out export/customs forms. Potentially, each country
charges a different amount on packages to their country.
Because the PCB "cannot be bent during processing", it has
to be sent parcel post, rather than first class mail, which
is much more standardized. The cheapest rate was over $9 to
Canada and the most expensive were several European
countries just under $15! I was stunned. I still sent the
packages, but everyone in Europe only has a $2.62 credit as
that's what I assumed the charge would be plus a little
more. I told people read the postage cost on the outside and
remit that amount less $2.62 since you've already paid that.
In most cases, that make the board stupidly expensive.
If the European Union has one rate for parcels,
my solution is to sell a bunch of boards to one place in the
Union and let people order from them. Same for the Pacific
Rim. Another solution is to find someone who likes waiting
in post offices and filling out forms and let them handle
the foreign orders. The third alternative is to not take
foreign orders, but that's unacceptable to me.?
So,
if you have some great idea for solving this problem, please
write me off-line so we don't chew up bandwidth here. I'm
good in QRZ.com. If something looks like it will work, I'll
inform the group.
Also,
I'll post to the group when the new shipment of boards comes
in.
Jack, W8TEE
Groups.io
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Re: Spurious RF at beginning of transmission
Folks have been reasonably certain of that on Bitx rigs for about 15 years now. ?A simple fix for the kerchunk into the headphones when entering receive was recently posted here, and there have been many others. ?The transmit kerchunk you describe has not been addressed so much. ?Easier to fix now that we have the Raduino, could shut down the Si5351 VFO buffer at CLK2 until that kerchunk is over with. ?Though 60ms is a rather long time, if using VOX that timeout I'm suggesting could easily clip off something significant. ?Let us know when you find a better fix.
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On Wed, May 31, 2017 at 02:07 pm, Bob wrote:
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.
?
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Speaking of encoders, does anyone know what size nut fits the shaft on a KY-040?? I have an encoder in the junk box but it is a eunuch.
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Re: Spurious RF at beginning of transmission
Arrghh -- sorry, phone call and I hit the wrong button.Continuing ...
When the radio goes into TX, that cap has to charge up via R127 -- which takes a LONG time. ?During that time, Q12 is also powering up and C122 has been sitting at zero volts, so it starts charging as well. ?This is the response of the Microphone Amplifier to the rising edge of the TX signal -- and the net result is that the Balanced Mixer (T4/D15/D16) is knocked out of balance until the amplifier stabilizes. ?The result of that is a spurious RF transmission that looks like the one I have attached as a file. ?The RF rises almost immediately to about 5-8 watts, within 5 ms drops down to about 3 watts, builds back up to 5-8 watts in another 5 ms, then slowly decays over a period of 60 ms decays down to close to zero. ?(All of this observed with the PTT line held).
That's pretty much the equivalent of a DOT at 20 WPM. ?You can hear that TX burst clearly on a monitor receiver.
When sending CW that initial burst may be masked by the first element as long as the speed is slow enough (< 20 WPM).
Since the unintended RF burst is caused by the transient response of the stage being powered up, a more optimal solution would be to keep that stage powered at all times, but shunt the audio to the base of Q12. ?Reducing the size of C124 would help shorten the burst.
73, Bob, WB4SON
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I got 10 ea.? WITH Threaded Bushing on eBay for less than $10.?
BUT, you have to WAIT!? Probably 4 Weeks on some Chinese orders.
I am using a non threaded one temporarily in the meantime.
On 5/31/2017 2:01 PM, Bruce Harvey
wrote:
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Thanks Ken,
Just what? want.
On the encoder,? was thrown by the threaded shaft part.?
On looking at pictures, now I see, some bushings are not
threaded.? Guess I needed the word "bushing"? :-)
73,
Bruce
On 2017-05-31 5:52 PM, Ken wrote:
forgot the encoder
73 Ken
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Spurious RF at beginning of transmission
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. ?During that time, Q12 is also powering up and C1
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Re: W8TEE TFT/VFO Board from FDIM talk
Thanks Ken,
Just what? want.
On the encoder,? was thrown by the threaded shaft part.? On
looking at pictures, now I see, some bushings are not threaded.?
Guess I needed the word "bushing"? :-)
73,
Bruce
On 2017-05-31 5:52 PM, Ken wrote:
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forgot the encoder
73 Ken
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Re: Raduino_v1.13 with scan function released
Yes, I think you got it. ?But better than adding a trim cap at C103 is to hook up the Raduino's CLK0 to replace the analog oscillator entirely, like the uBitx is doing for the BFO. ?Allard says he is looking into supporting this in a future sketch. ?This would allow the Nano to flip the BFO freq depending on if you want USB, LSB or CW, transmit or receive. ?All of those can affect where we might want the BFO placed, in addition to where the crystal filter happens to be centered on your rig. ?What's more, driving the BFO from CLK0 allows us to tune your CW carrier through the filter's range, and figure out what the shape of the filter is by monitoring the power of the outgoing CW carrier.
For now, if all you care about is sufficient drive when transmitting CW, I suggest you just put in a 10k resistor (instead of Allard's original 47k).
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On Wed, May 31, 2017 at 01:11 pm, John Smith wrote:
Is this a little bit more about what Peter was saying about "the relationship between the BFO crystal and the crystal filter bandpass"?
?
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Re: W8TEE TFT/VFO Board from FDIM talk
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On Wed, May 31, 2017 at 4:22 PM, Bruce Harvey <bharvey@...> wrote:
On 2017-05-27 4:57 PM, Jack Purdum via
Groups.Io wrote:
KY040 (threaded shaft)
encoders
Hi guys,
I've been trying to locate an Arduino Mega 2560 Pro Mini board
source that is available to Canadian buyers.
Any suggestions would be appreciated.
Also, I haven't found a KY040 (threaded shaft) encoder.
Other than that I think I have the other parts located and
ordered.
Bruce, VE1II
|
Re: W8TEE TFT/VFO Board from FDIM talk
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Show quoted text
On Wed, May 31, 2017 at 4:22 PM, Bruce Harvey <bharvey@...> wrote:
On 2017-05-27 4:57 PM, Jack Purdum via
Groups.Io wrote:
KY040 (threaded shaft)
encoders
Hi guys,
I've been trying to locate an Arduino Mega 2560 Pro Mini board
source that is available to Canadian buyers.
Any suggestions would be appreciated.
Also, I haven't found a KY040 (threaded shaft) encoder.
Other than that I think I have the other parts located and
ordered.
Bruce, VE1II
|
Change from TX offset to RX offset in future code versions?
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 and was happily working CW. ?He very carefully calibrated the radio and chose a 600 Hz CW offset. ?Even so he noticed a problem on transmit. ?If he set the display of his BITX40 to 7.039.0 MHz, he noticed that his signal was reported as 7.038.4 on the spotting networks. ?It appeared that the CW Offset was being applied on transmit rather than receive. The reference point for amateur transmissions is the transmit carrier frequency. ?That is what is entered into one's log. ?That's all the regulatory agencies care about -- - what your transmit frequency is. ?You would look at your display frequency and write that down. ?So if the display says 7.039.0 MHz that is what you log and that should be the transmit frequency. However, in the case of 1.13 firmware, that is not the case. ?the CW_OFFSET is applied at TX time. ?The following three lines of code show that CWoffset is set to the CW_OFFSET (established at calibration time), the frequency is then set to the display frequency plus that offset by setFequency, and the PTT switch is activated.
? ? ? CWoffset = CW_OFFSET;
? ? ? setFrequency(frequency);
? ? ? digitalWrite(TX_RX, 1); // activate the PTT switch - go in transmit mode
?
When the transmission is completed (the timer expires), the code sets the radio back into RX, then clears out CWoffset, and sets the frequency back to the dial frequency (with no offset).
? ? digitalWrite(TX_RX, 0); // release the PTT?switch - go back to receive mode
? ? CWoffset = 0;
? ? setFrequency(frequency);
?
This is actually the opposite of what should ideally be going on. ?As it stands now, the TX Carrier frequency is not what the user is expecting, and it means that spotting networks are off. Maybe there is some reason like code size that the TX offset is used, but to get the BITX40 on the same page with other radios, to have their frequency display agree and their spots to be accurate, changing to RX offset would be best. 73, Bob, WB4SON
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Re: W8TEE TFT/VFO Board from FDIM talk
On 2017-05-27 4:57 PM, Jack Purdum via
Groups.Io wrote:
KY040 (threaded shaft)
encoders
Hi guys,
I've been trying to locate an Arduino Mega 2560 Pro Mini board
source that is available to Canadian buyers.
Any suggestions would be appreciated.
Also, I haven't found a KY040 (threaded shaft) encoder.
Other than that I think I have the other parts located and
ordered.
Bruce, VE1II
|
Re: Raduino_v1.13 with scan function released
Jerry, you said "That variation is due to how the BFO lands on the edge of the crystal filter, so different rigs wind up with different drive levels into the IRF510."? Is this a little bit more about what Peter was saying about "the relationship between the BFO crystal and the crystal filter bandpass"? I am just starting thinking about this stuff, and so far it seems necessary to have a trim cap at C103 to adjust for best audio power and quality. And now something similar for CW BFO frequency. Would this help Allard with his efforts on CW?? Here is the link to Peter's post on the subject of "Improved Audio Hack. ? /g/BITX20/message/27222
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Re: Raduino_v1.12 released
Hi Allard,
I would like to confirm perfect CW (Carrier) tone with 10k resistor
73, Yiannis, SV5FRI
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All:
I just spent an hour at the post office while they processed each foreign order. Last night I spent another several hours filling out export/customs forms. Potentially, each country charges a different amount on packages to their country. Because the PCB "cannot be bent during processing", it has to be sent parcel post, rather than first class mail, which is much more standardized. The cheapest rate was over $9 to Canada and the most expensive were several European countries just under $15! I was stunned. I still sent the packages, but everyone in Europe only has a $2.62 credit as that's what I assumed the charge would be plus a little more. I told people read the postage cost on the outside and remit that amount less $2.62 since you've already paid that. In most cases, that make the board stupidly expensive.
If the European Union has one rate for parcels, my solution is to sell a bunch of boards to one place in the Union and let people order from them. Same for the Pacific Rim. Another solution is to find someone who likes waiting in post offices and filling out forms and let them handle the foreign orders. The third alternative is to not take foreign orders, but that's unacceptable to me.?
So, if you have some great idea for solving this problem, please write me off-line so we don't chew up bandwidth here. I'm good in QRZ.com. If something looks like it will work, I'll inform the group.
Also, I'll post to the group when the new shipment of boards comes in.
Jack, W8TEE
Groups.io Links:
You receive all messages sent to this group.
_._,_._,_
|
Re: Signal Meter and 10m conversion for Bitx40 ?
Dennis has the AGC board done, with an S meter takeoff point. (See pix.) We're trying to combine the AGC, CW, and speech compressor boards onto one board to see how it works. Not sure how long that will take.
Jack, W8TEE
From: Jerry Gaffke via Groups.Io <jgaffke@...>
To: [email protected]
Sent: Wednesday, May 31, 2017 12:02 PM
Subject: Re: [BITX20] Signal Meter and 10m conversion for Bitx40 ?
Here's a very simple S-meter: ? I suppose you could read it from the Arduino through an analog pin, and maybe convert the linear reading over to something logarithmic (traditionally 6 dB difference per S unit). Print the result to the display using printLine2() in the sketch. But that diode detector is not going to be very sensitive. A more accurate S-meter could be had by using an AD8307 (or AD8307 if you can deal with the pin spacing.) Not only does it have a 90 dB dynamic range, the output is logarithmic. ? Those parts are good down to DC, could be used after the audio pre-amp if you need the gain. As far as hitting other bands, you would need to replace the bandpass filter at L1,L2,L3 and the lowpass filter at L6,L7. Also adjust the Arduino sketch to move the VFO frequency appropriately. Power from the IRF510 will be down some when operating at 10 meters, and could be you will have trouble with the current board layout at those higher frequencies. Allard's sketch allows you to choose LSB or USB operation. Jerry, KE7ER On Wed, May 31, 2017 at 08:05 am, Jim McKay wrote:
I am looking for software and hardware advice to add a signal meter (ideally on the Raduino?1602 LCD - bottom line?) and also to convert the radio to 10m USB.
?
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hi
anybody interested in my mike.
i used the kit supplied mike insert and the tube from a marker pen. fits exactly
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Re: Signal Meter and 10m conversion for Bitx40 ?
The AD8310 is newer, cheaper, and slightly better, but those pins are on 0.65mm centers.
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On Wed, May 31, 2017 at 09:02 am, Jerry Gaffke wrote:
A more accurate S-meter could be had by using an AD8307 (or AD8307 if you can deal with the pin spacing.)
?
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Re: Building my own ubitx - question about mixers and mixer transformers
Most any level 7 mixer should work, such as the ADE-1 or SBL-1. ?The commercial ones are designed to give a flat response up to a ghz or two, so an appropriately hand built design appropriate for the operating frequency may outperform it, though choosing the correct core and number of windings is not something I'll be giving advice on. ?If you check the datasheets, you will see that the commercial mixer schematic is identical to what Farhan has on his diode ring mixers, so the same method of transmitting CW should work. ?The dual diode modulator on the uBitx is operating at 12mhz, and can be identical to what is on the Bitx40.?
There are a few issues with the uBitx as it now stands.?
With a 45mhz IF and a high side VFO, the receiver will be susceptible to images in the FM broadcast band. ?For example, when receiving at 25mhz, the vfo will be at 45+25 = 70mhz. ? An FM transmitter at 70+25 = 95mhz would be received as an image. ?So if you have strong FM broadcast transmitters in your area, you might consider upping the IF frequency some from 45 mhz. ?That would also make it easier to build a suitable front end lowpass filter that still lets through a 10m signal.
The second harmonic out of the push-pull IRF510's is not sufficiently attenuated unless you happen to have a spectrum analyzer handy to get the balance right. ?So, for example, you will likely need separate lowpass filters on 80 and 40 meters to be legal. ?Use C0G or NP0 caps in those filters and anywhere the actual capacitance value is critical, and the caps in in the lowpass filters need to be good for several hundred volts.
There might be some trouble with crosstalk when using all three outputs from the Si5351, especially if the SI5351 outputs are set to the higher drive levels. ?Will certainly work, though might give us extra birdies.
Farhan is still developing the uBitx, but has encouraged scratch builds as a way of getting more information on possible issues.
I think it will prove to be a very nice rig, better in many ways than the Bitx40 has been.
Jerry, KE7ER
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On Wed, May 31, 2017 at 08:55 am, David Feldman wrote:
1. I could not find specification for the transformers used in ubitx (alongside the BAT45S diodes), but I did eventually track down a mention from bitx40 on hfsigs.com as follows: ? ?T1,T2,T4,T5,T6,T7 : 10 turns trifilar on FT 37-43 core
Is this appropriate for the ubitx frequency regime (12 and 45 MHz)?
?
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Re: Building my own ubitx - question about mixers and mixer transformers
Dave WB0GAZ
In the early days of BITX most of us built our own transceivers that loosely followed the
original design by Farhan.? Historical information on those builds cover most of your
questions and can be found by browsing back over the group discussions.? - You can build your own mixers.? These might be simple as-built units with
1N4148 diodes and FT37-43 transformers.? !0 turns may be a bit much
for operation at the upper extremes of HF range, but you can test this by
measuring input versus output of the transformers with an appropriate load.
- Many of the commercial mixers can be used (SBL, etc.).? Almost all should
perform adequately.? There is much room for discussion (argument...?)
about whether commercial mixers or carefully built homemade mixers are
best.? Lower threshold diodes should require less LO drive voltage.? Carefully
matched diodes and transformer windings should also improve performance.
- Binocular transformers do find use in the RF PA of may QRP rigs.? You can
use stacks of conventional toroidal cores as work-alike alternatives.? Same
winding technique is used for both binocular cores and stacked toroid cores.
There are many myths, opinions, facts, and opinionated facts regarding which mixer is best or worse.? I personally would build my own carefully designed mixers, but leave
room for substituting alternative mixers for testing and evaluation purposes.? This
way you can determine for yourself which is best for you.? It may be that the best?
HF mixer will be different from the best BFO mixer.? It is probably not a one-size-fits-all
situation.
Arv
_._
On Wed, May 31, 2017 at 9:55 AM, David Feldman via Groups.Io <wb0gaz@...> wrote: Hello (and thanks to the moderator for approving my request to join)!
I am implementing my own ubitx and have a couple of questions about the mixers and mixer transformers (which don't seem to be specified on the project website):
1. I could not find specification for the transformers used in ubitx (alongside the BAT45S diodes), but I did eventually track down a mention from bitx40 on as follows:
T1,T2,T4,T5,T6,T7 : 10 turns trifilar on FT 37-43 core
Is this appropriate for the ubitx frequency regime (12 and 45 MHz)?
2.
There were some mentions of "tv transformer cores" - binocular - but no specification or identifier.
Are these a suitable alternative?
3.
Could I use packaged minicircuits mixers (such as ADE-1 or similar Level-7 mixer) in lieu of the transformer+bat45s design?
If so, how do I "unbalance" the ADE-1 for CW transmit in the 45 MHz-to-RF mixer stage? Would injecting a positive bias voltage into the IF port work (if so, recommended voltage, current and means to isolate normal RF flow)?
Thanks very much, looking forward to this project!!
73 Dave WB0GAZ wb0gaz@...
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Bob
