I had my WA2EBY toroids wound for me by the same guy who does the toroid sets for Elecraft, to Elecraft's approved standards. I am waiting for the rest of the parts to arrive from Mouser, with the exception of the SMD resistors, which are on order from China. The ones from Mouser are on back-order, and won't arrive until NOVEMBER (!), and I really don't want to wait quite that long...

Rich

KC8MWG

On Friday, July 7, 2017, 9:04:32 PM EDT, Jack Purdum via Groups.Io <econjack=[email protected]> wrote:

Diz's company, Kits And Parts, is a gold mine for hard-to-find caps and toroids. A friend of mine has one of his One Watters and it's a fun little rig. Keep him in mind when you're building.

Jack, W8TEE

---

From: Leonard <dredger@...>
To: [email protected]
Sent: Friday, July 7, 2017 8:23 PM
Subject: Re: [BITX20] 80m hexfet power amplifier by W7ZOI

"Yeah, I forgot about Diz. He's good. He also has a toroid kit for the
WA2EBY LPF assembly, but not a cap kit as far as I know...

john
AD5YE"

Diz might put together a mica cap kit for the wa2eby amplifier. Someone would have to ask him. That's how the toroid kit came to be. I asked him. I bought all of the mica caps from Mouser.




Leonard

Within the hour I will be uploading Release 1.00 of the software for the TFT mods discussed earlier. This software assumes you are using the PCB, AD9850, Mega 2560 Pro Mini, and rotary encoder as was discussed here earlier. There are three files:?
? ?1) B40SoftwareRel0100.ino ?-- ?the main sketch for the Mega
? ?2) MorseCode.h -- ?a supporting file that holds a number of data items used for the (pending) CW mode.
? ?3) Assembly Manual -- ?only one page right now, and that centers around how to get the Voltage field on the display to work properly. It also discusses the required directory structure needed to compile the files.

I apologize for the long time it took to get this out there, but there have been numerous fires that needed to be stomped out first. Please report bugs as soon as you find them so others don't get frustrated.

Jack, W8TEE

Is there a circuit diagram with 'hovers' over the components? My eyesight and computer schema do not lend well to viewing the diagram at hfsigs.

Low power tuning?? No problem.? I used the CW trick (part of the
recent Raduino mods) with the 10K resistor but instead of hooking up the other end of the resistor to the raduino, I hooked it up to a 100K pot to 5v thru a switch.? Switch off, the BitX operates normally.? Switch on, the BitX sends a carrier, of whatever power you want based on where the 100K pot is set, when you hit the PTT.? With the 100K you can take it down to nothing.? It's very possible a 25K or 50k would also work satisfactorily but I didn't check, the 100K was handy.

Vince.




On 07/08/2017 12:51 PM, Arv Evans wrote:

Rich? KC8MWG

MOSFETs will blow from over-current faster than I can reach the
controls, but
I am old and slow so your mileage may vary.

Tune up has always been one of my complaints about the BITX design.? We
need a low-power output setting for adjusting the ATU, and then ability
to switch
to higher power for normal use.? Back in the BITX20A and BITX17A days I
used
an audio oscillator with two switch selected output levels.? Low level
was used
to generate less than 0.1 watts output for tuning the ATU and high level
AF out
for sending CW.? This works if the antenna is not too far from 50 ohms,
but does
not protect the RF PA if no antenna is connected.

Some have experimented with current-limited power supplies for the PA stage.
I'm not sure how effective that might have been.

I wonder what might happen if a small resistance and bypass capacitor were
placed in series with the IRF510 source lead?

Back in the bad old days of vacuum tubes and thermionic emission we used
small inductances and parallel capacitors? in plate circuits to minimize
parasitic
oscillations.? ? The oscillation mode is different with MOSFETs? but
this might
warrant? further exploration.

ALC circuits for the RF PA stage might be useful for detecting and
taming some
oscillations, but might be tricky to adjust for SSB use.

I wonder if the RF PA voltage might be reduced to some low level for tune-up
and then switched to higher voltage for normal operation?? Using low
voltage
on the drain lead during tune-up could cause non-linearity and spurious
outputs but for short-term tune-up action this might not be too
objectionable.

Part of the attraction of BITX designs is that is always potential for
modification
and hopefully improvement.

Arv? K7HKL
_._



On Sat, Jul 8, 2017 at 8:36 AM, Richard Andrew Knack via Groups.Io
<ihc73scout2=yahoo.com@groups.io
<mailto:ihc73scout2=yahoo.com@groups.io>> wrote:

? ? How quickly will IRF-510's blow? And how much power will it take? In
? ? other words, if you have a transceiver or an amp that has them for
? ? finals, do you have time to use an automatic antenna tuner to get an
? ? impedance match? Or will the finals blow while the tuner is running
? ? through relays and inductances trying to find a match?

? ? Rich
? ? KC8MWG



? ? On Saturday, July 8, 2017, 10:31:21 AM EDT, Arv Evans
? ? <arvid.evans@... <mailto:arvid.evans@...>> wrote:


? ? K3HJP

? ? Like Raj said...the IRF510 is probably blown, usually due to
? ? transmitting into something other
? ? than a 50 ohm load.? If the output impedance is too high the final
? ? will go into oscillation and
? ? self-destruct.

? ? Arv? K7HKL
? ? _._

? ? On Sat, Jul 8, 2017 at 7:32 AM, <Kc3hjp@...
? ? <mailto:Kc3hjp@...>> wrote:

? ? ? ? Hi guys, I finally got around to finishing my Bitx40 project.
? ? ? ? Everything works but it will not transmit. This has me
? ? ? ? scratching my head. Here are some details.

? ? ? ? - when I press the PTT on the mic I can hear the relay pull in
? ? ? ? and receive audio goes away as it should.
? ? ? ? - I've verified that I have 12vdc on the PA connection and it's
? ? ? ? wired in the right direction.
? ? ? ? - mic element ohms out properly and it's wired in the right
? ? ? ? direction according to instructions
? ? ? ? - 152mA on receive
? ? ? ? - 260mA on transmit with no audio
? ? ? ? - current may change by .001mA when yelling into the mic
? ? ? ? - set PA bios pot makes no difference in current reading with
? ? ? ? mic keyed (audio/no audio)
? ? ? ? - mic element 0.877k ohms in one direction and 1.101k ohms in
? ? ? ? other direction
? ? ? ? - same mic ohm values on the mic connector and board connector
? ? ? ? - 12vdc between the Gate and Drain of the PA. No voltage between
? ? ? ? the Gate and Source when mic is keyed

? ? ? ? Any ideas?

--
? Michigan VHF Corp.? ?? ?
? ? ? ? ? ? ? ? ? ? ? ? ?

Joe,

do something like this:

? if (USB) // if we are in UPPER side band mode
? ? si5351.set_freq((IF + Dial_freq) * 100ULL, SI5351_CLK2);
? else // if we are in LOWER side band mode
? ? si5351.set_freq((IF - Dial_freq) * 100ULL, SI5351_CLK2);

In other words you just flip the VFO freq to the other side of the IF.

The IF is (approx) 12 MHz.
so for LSB: VFOfreq = 12-7= 5MHz
and for USB: VFOfreq = 12+7= 19Mhz

73 Allard PE1NWL

On Sat, July 8, 2017 20:36, Joe wrote:
> Vince,
>
> Thanks for the reply.
> Yes, i have looked at both methods. But no luck in adding to existing
> code.
>
> I tried using code from Peter Flemming, as he use clk2 and clk0 for vfo
> and
> bfo.
> I built a bitx40 and used this method. It works fine in his sketch but my
> skill level has not been successful in adding it to our code.
>
> I also looked at the current Raduino method but no go for me either.
>
> Frustrating, not being able to add 6 or 7 lines for a solution.
>
> Joe
> VE1BWV
>
> On Sat, Jul 8, 2017, 1:40 PM Vince Vielhaber <vev@...> wrote:
>
>> Joe, there are two ways to get USB.? The first way is what's offered in
>> Allard's Raduino project which shifts CLK2 to 19MHz.? The second way
>> (which I'm going to be doing when life gets outta the way and lets me
>> finish it) is to scrap the current BFO and use CLK0 for the BFO.
>>
>> Vince.
>>
>>
>> On 07/08/2017 12:21 PM, Joe wrote:
>> > Hi,
>> >
>> > Myself and Adrian (VK4L) have been working on code developed by PD8W.
>> > We believe it would be a very nice addition to software choices for
>> our
>> > fellow hams.
>> >
>> >
>> > It works with an atmega 2560, a SI5351, a TFT colour display.
>> > Just plug the display into the atmega and wire up the SI5351 along
>> with
>> > a few buttons.
>> > Easy and that part works great.
>> >
>> >
>> > After much effort I have been able to make the code work(almost),
>> > It currently has a nice display layout and displays everything fine on
>> > the TFT colour Display.
>> > I tunes the Bitx40? very smoothly( rotary encoder).
>> > I added a button to change the vfo freq time stepping it? also works
>> well.
>> >
>> >
>> > Our goal is to *add USB,* so we can use it for *Digital modes.*
>> >
>> >
>> > After burning many brains cells, (and at my age, I cannot afford to
>> burn
>> > to many) I cannot seem to get my head around making the code work for
>> USB,
>> > I tried cut and pastes from many codes and still no success.
>> >
>> > We are both aware the existing code could be much better structured
>> > From looking around the internet, I don't see any code offering the
>> > functions with a good colour display.
>> >
>> > I realize Jack , W8TEE is working on a great project and I have his
>> > boards and parts populated and near ready.
>> >
>> > However, this project is different. It offers off the shelf usage of
>> > standard Arduino modules, and a plugin TFT Colour Display, and
>> minimal
>> > components..
>> > Unfortunately, the author is not available for help to finish off a
>> few
>> > items.
>> >
>> > It is is a pain to decode, but we are hoping someone can give us a
>> hand
>> > getting over this *1 major? issue (adding USB function*).
>> >
>> > Once this is done, the code will be completely functional and
>> available
>> > to anyone? who would like it.
>> > The? additional items to display for tx / rx etc ... should not be a
>> big
>> > issue.
>> >
>> > I have attached the code below
>> >
>> >
>> > Any help would be much appreciated.
>> >
>> > Joe
>> > VE1BWV
>> >
>> >
>> >
>>
>> --
>>? ? Michigan VHF Corp.? ?? ?
>>? ? ? ? ? ? ? ? ? ? ? ? ? ?
>>
>>
>>
>>
>

Low power tuning?? No problem.? I used the CW trick (part of the
recent Raduino mods) with the 10K resistor but instead of hooking up the other end of the resistor to the raduino, I hooked it up to a 100K pot to 5v thru a switch.? Switch off, the BitX operates normally.? Switch on, the BitX sends a carrier, of whatever power you want based on where the 100K pot is set, when you hit the PTT.? With the 100K you can take it down to nothing.? It's very possible a 25K or 50k would also work satisfactorily but I didn't check, the 100K was handy.

Vince.




On 07/08/2017 12:51 PM, Arv Evans wrote:

Rich? KC8MWG

MOSFETs will blow from over-current faster than I can reach the
controls, but
I am old and slow so your mileage may vary.

Tune up has always been one of my complaints about the BITX design.? We
need a low-power output setting for adjusting the ATU, and then ability
to switch
to higher power for normal use.? Back in the BITX20A and BITX17A days I
used
an audio oscillator with two switch selected output levels.? Low level
was used
to generate less than 0.1 watts output for tuning the ATU and high level
AF out
for sending CW.? This works if the antenna is not too far from 50 ohms,
but does
not protect the RF PA if no antenna is connected.

Some have experimented with current-limited power supplies for the PA stage.
I'm not sure how effective that might have been.

I wonder what might happen if a small resistance and bypass capacitor were
placed in series with the IRF510 source lead?

Back in the bad old days of vacuum tubes and thermionic emission we used
small inductances and parallel capacitors? in plate circuits to minimize
parasitic
oscillations.? ? The oscillation mode is different with MOSFETs? but
this might
warrant? further exploration.

ALC circuits for the RF PA stage might be useful for detecting and
taming some
oscillations, but might be tricky to adjust for SSB use.

I wonder if the RF PA voltage might be reduced to some low level for tune-up
and then switched to higher voltage for normal operation?? Using low
voltage
on the drain lead during tune-up could cause non-linearity and spurious
outputs but for short-term tune-up action this might not be too
objectionable.

Part of the attraction of BITX designs is that is always potential for
modification
and hopefully improvement.

Arv? K7HKL
_._



On Sat, Jul 8, 2017 at 8:36 AM, Richard Andrew Knack via Groups.Io
<ihc73scout2=yahoo.com@groups.io
<mailto:ihc73scout2=yahoo.com@groups.io>> wrote:

? ? How quickly will IRF-510's blow? And how much power will it take? In
? ? other words, if you have a transceiver or an amp that has them for
? ? finals, do you have time to use an automatic antenna tuner to get an
? ? impedance match? Or will the finals blow while the tuner is running
? ? through relays and inductances trying to find a match?

? ? Rich
? ? KC8MWG



? ? On Saturday, July 8, 2017, 10:31:21 AM EDT, Arv Evans
? ? <arvid.evans@... <mailto:arvid.evans@...>> wrote:


? ? K3HJP

? ? Like Raj said...the IRF510 is probably blown, usually due to
? ? transmitting into something other
? ? than a 50 ohm load.? If the output impedance is too high the final
? ? will go into oscillation and
? ? self-destruct.

? ? Arv? K7HKL
? ? _._

? ? On Sat, Jul 8, 2017 at 7:32 AM, <Kc3hjp@...
? ? <mailto:Kc3hjp@...>> wrote:

? ? ? ? Hi guys, I finally got around to finishing my Bitx40 project.
? ? ? ? Everything works but it will not transmit. This has me
? ? ? ? scratching my head. Here are some details.

? ? ? ? - when I press the PTT on the mic I can hear the relay pull in
? ? ? ? and receive audio goes away as it should.
? ? ? ? - I've verified that I have 12vdc on the PA connection and it's
? ? ? ? wired in the right direction.
? ? ? ? - mic element ohms out properly and it's wired in the right
? ? ? ? direction according to instructions
? ? ? ? - 152mA on receive
? ? ? ? - 260mA on transmit with no audio
? ? ? ? - current may change by .001mA when yelling into the mic
? ? ? ? - set PA bios pot makes no difference in current reading with
? ? ? ? mic keyed (audio/no audio)
? ? ? ? - mic element 0.877k ohms in one direction and 1.101k ohms in
? ? ? ? other direction
? ? ? ? - same mic ohm values on the mic connector and board connector
? ? ? ? - 12vdc between the Gate and Drain of the PA. No voltage between
? ? ? ? the Gate and Source when mic is keyed

? ? ? ? Any ideas?

--
? Michigan VHF Corp.? ?? ?
? ? ? ? ? ? ? ? ? ? ? ? ?