I just used a trim cap In c103 and adjusted for best audio on transmit but for cw out put will be near nil I found so you could use transistor switch to switch? in 2 trim caps one for ssb and one for cw tap the voltage from the wire that go to d6 connector p3 pin 15 on raduino or just use a switch for ssb/cw?

Peak the cw trim cap for good output but make show your transmit is on frq may not be the best way chris

Michael (and others) -- thanks!!! This is a much-wanted improvement not
only for our EOC, but for others of us as well.


Today I improved on the code and got it so you can zip between bands. By
simply draping a wire from the antenna port of a modern rig near the
heteodyne oscillator tube, I had very loud signals and was able to
sequentially find most of the heterodyne crystals (the receiver wouldn't go
higher than 30 MHz) and wride down the values --- the code now chooses the
correct numbers to add in to the equation based on what band you've zipped
to. Of course, you still need to turn the BANDSWITCH on the Heathkit!!!!


It occurred to me that a very useful thing for hams is to have a way to
listen to WWV. The 10 MHz WWV was so far away from the tuned circuits in
the Heathkit that I couldn't get that to work very well, but I *was* able to
get the rig to receive on 15 MHz!!! Something it has never been able to do
before....and although propagation isn't that good, I heard the "tick tock"
and "DING!" a couple of times so it actually is receiving WWV.


I tested the computer control again today from a computer running the WINLNK
server software (RMS_TRIMODE) and it worked fine. The other day I ran it
overnight and in the morning it was still working. I don't have the full
write up of the protocol so I could be missing "sync" information --- but my
code is sending "ACK" and maybe that helps? Dunno --- but it works.



I'm not a github expert. Is it better for me to try to create whatever
kind of account is needed to store software there? (How much work is
that????) Or would it be better for one of the experts on this forum to get
the sketch and post it? Doesn't matter to me -- it is mostly Allards work
with just some changes to handle my needs.


I had significant issues with the "cannot rename core/core.a" error with the
IDE.....lopped out some of Allards keyer subroutines thinking my code might
be too long --- but that didn't help....found another way around it.
Already loaded the upgraded arg subdirectory....didn't help. Copied to a
new sketch and opened as Administrator -- and was able to compile again.
Ah.....



You can use this just as it is with a Heathkit, but if you measure your
heterodyne crystals you'll do much better. It seems to me that Heathkit
got much more accurate BFO crystals---they were very close to stated
frequency. Their heterodyne crystals tended to be 3 kHz low, and the
Raduino 25 MHz board tends to be (n of 2) 4 kHz high. Correct those in
the #define statements and the rig is right on frequency.



Thanks for all the help!!!!

Gordon



________________________________
From: [email protected] <[email protected]> on behalf of Michael Monteith via
Groups.Io <michael_r_monteith@...>
Sent: Wednesday, December 6, 2017 10:08 AM
To: [email protected]
Subject: Re: [BITX20] Digitally Controllable Heathkit Vacuum Tube Radio

Gordon,
Congratulations. It's good to see this kind of work going on. I love
playing around with microcontrollers and now integrating them with my ham
projects is right up my ally.
Keep up the great work.

73, Michael
KM4OLT

I found if I got ssb good then cw out put was low but as I don't use cw I peaked for good ssb I get 8 watts for 12,v and up to 13watts for almost 13v the photos for my 60m bitx I get the same on my 40m set I get good audio reports with supplied mic capsule chris G0WFH

On 6 Dec 2017 19:43, "Allard PE1NWL" <pe1nwl@...> wrote:

Perhaps his BFO is slightly off frequency.
If it's slightly too high, then in SSB mode some carrier may pass through
the filter which might explain the noise during the PTT transition.
It could also explain why he has lower output in SSB than in CW mode.
Just a guess.

73 Allard PE1NWL


On Wed, December 6, 2017 19:48, Jerry Gaffke via Groups.Io wrote:
> Good to hear it works.
>
> In CW mode, the final amp is driven hard because the amount of bfo that
> sneaks through the crystal filter
> varies depending on how the bfo and filter are aligned and the exact shape
> of the crystal filter skirts. ?
> So the IRF510 is likely running in something like class C, and thus
> producing greater output than it does for phone.
> But if you drive the IRF510 that hard during phone, the transmission will
> be distorted.
>
> Your 4w out for phone might be about right.? Depends on how loud you are
> shouting and the voltage you feed into the IRF510. ?
> You could try an external amp for the microphone, or try this mod from Raj
> to increase the gain of the existing amp: ?
> ? ??/g/BITX20/message/30249
> Then adjust R136 to avoid distortion from driving the IRF510 too hard.
>
> Your squishing sound is probably due to how the Bitx40 switches 12v from
> RX to TX circuits,
> especially the microphone amp and audio pre-amp.
> Allard's latest code addresses this by using delays in software, but some
> may still sneak by.
> Here's an old thread about noises in the headphones during PTT
> transitions,
> there have been plenty of other such threads:
> ??/g/BITX20/message/25870
>
> Jerry, KE7ER
>
> On Wed, Dec 6, 2017 at 07:40 am, David Holland wrote:
>
>>
>> I have finally (hopefully) got my BitX-40 up and running.? I have two
>> problems that I hope someone can help with.? The first is that when I
>> go
>> press they key to go to TX using semi-QSK mode I get a short squishing
>> sound from the speaker.? It does not seem to affect CW operation.?
>> It's
>> very annoying though!
>> My 2nd problem is with the relative power outputs between CW and SSB.?
>> Using a dummy load and a scope and the formula (.707 x peak voltage)
>> squared then divided by 50 I get approximately 7watts on CW but only 4
>> on
>> SSB.? Any ideas please?
>> Thank you.
>

Good to hear it works.

In CW mode, the final amp is driven hard because the amount of bfo that
sneaks through the crystal filter
varies depending on how the bfo and filter are aligned and the exact shape
of the crystal filter skirts. ??
So the IRF510 is likely running in something like class C, and thus
producing greater output than it does for phone.
But if you drive the IRF510 that hard during phone, the transmission will
be distorted.

Your 4w out for phone might be about right. ??Depends on how loud you are
shouting and the voltage you feed into the IRF510. ??
You could try an external amp for the microphone, or try this mod from Raj
to increase the gain of the existing amp: ??
?? ????/g/BITX20/message/30249
Then adjust R136 to avoid distortion from driving the IRF510 too hard.

Your squishing sound is probably due to how the Bitx40 switches 12v from
RX to TX circuits,
especially the microphone amp and audio pre-amp.
Allard's latest code addresses this by using delays in software, but some
may still sneak by.
Here's an old thread about noises in the headphones during PTT
transitions,
there have been plenty of other such threads:
????/g/BITX20/message/25870

Jerry, KE7ER

On Wed, Dec 6, 2017 at 07:40 am, David Holland wrote:

I have finally (hopefully) got my BitX-40 up and running.?? I have two
problems that I hope someone can help with.?? The first is that when I
go
press they key to go to TX using semi-QSK mode I get a short squishing
sound from the speaker.?? It does not seem to affect CW operation.??
It's
very annoying though!
My 2nd problem is with the relative power outputs between CW and SSB.??
Using a dummy load and a scope and the formula (.707 x peak voltage)
squared then divided by 50 I get approximately 7watts on CW but only 4
on
SSB.?? Any ideas please?
Thank you.

I have finally (hopefully) got my BitX-40 up and running.? I have two problems that I hope someone can help with.? The first is that when I go press they key to go to TX using semi-QSK mode I get a short squishing sound from the speaker.? It does not seem to affect CW operation.? It's very annoying though!
My 2nd problem is with the relative power outputs between CW and SSB.? Using a dummy load and a scope and the formula (.707 x peak voltage) squared then divided by 50 I get approximately 7watts on CW but only 4 on SSB.? Any ideas please?
Thank you.

I have been searching for the updated schematic with xtal filter and band pass filters.
Can anyone point me in the right direction?