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The initial Raduino?software effort basically works!? ?

Using the bitx40 Raduino, I can fully tune (one any one band) the Heathkit SB-100 vacuum tube radio now.? ?In order to change to a different band you do two things:

1)? change the physical bandswitch of the Heathkit (which brings in different tuned circuits, & heterodyne crystals)

2)? turn the raduino freq control full to the direction desired -- I have it written so it speeds through jumping QUICKLY?until it hits a valid HAM BAND and then it moves through at a sedate pace of jumps so you can stop close to where you want --- the code then automatically utilizes the correct heterodyne oscillator and bfo oscillator crystal frequencies for the Heathkit and provide the correct VFO frequency to put the rig where you wanted it.??

[For one band and for the? usb/lsb? BFO's we have already measured those cyrstals and on that band it is pretty perfect....will measure all the other crystals tomorrow after some sleep so it becomes near perfect there also. ]

And the code retains the minimalist FT857d computer-controllable features meaning software like WINLINK EXPRESS or WINLINK RMS TRIMODE can drive the rig (within one portion of a band) to any frequency needed.? ?That feature is important to allow the auto-RF-forwarding of WINLINK to function in the event of massive Internet Failure --- remember,this project was one palliative measure in the event of EMP.? ?

I am so appreciative of everything that Allard -- and Pavel --- wrote which I've utilized.? ?The top disclaimer in the code from Allard remains intact, and although I basically had to start fresh to do the FT857d emulation, I will add some statement of how much Pavel's code made it possible.??

It has been a good day.

Gordon?

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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

Using the bitx40 Raduino, I can fully tune (one any one band) the Heathkit SB-100 vacuum tube radio now.? ?In order to change to a different band you do two things:

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It wasn't hard at all.? ?The levels appeared to be very similar and in my case the vfo of the tube rig was set for 50 ohms also.??

Plain old square wave, worked fine.? ?

Hven't formally written it up yet --- will have that done wtihin a week or two...here's an oveview document:

?

I have designed a little circuit to provide some EMP protection for the Raduino, and am waiting on boards to return....

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Thanks Jack,? given the current inability to get raduinos, that is a viable alternative that i've considred.

Right now I just built my first swr meter kit and have mapped out (this is new stuff for me!) how to connect the Adafruit si5351 to a nano to drive a resistive swr bridge (next project) and make an antenna tuner.? ? ?The swr meter kit I soldered last night is to make an arduino based SWR meter.? ?This is quite fun stuff!!!!? But I'm sure you know that.....

I have two Heathkits controlled by Raduino's current and the third is on the way.? ?Modified my code to have a small array to keep the various crystalls from several heathkits.

I should be able to get a single bander to work as well, and cover a wider frequency range than their original.? This technology is amazing.

cheers,

gordon

If you're going to use the Si5351, take a look at QRP-Labs Si5351A synthesizer kit.

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Hey, I got 2 SI5351 PCBs and Kits.? Better too!? Don't buy elsewhere.

Small or Lotsa Clocks with extra I2C Address and 8 clocks (the 20 Pin IC).

Ha.. Ha..? Ask Vince on this list about Lotsa Clocks!

Email for info, I got lots of PCBs.

If you're going to use the Si5351, take a look at QRP-Labs Si5351A synthesizer kit.

Jack, W8TEE

---

From: John P <j.m.price@...>
To: [email protected]
Sent: Monday, January 8, 2018 2:44 PM
Subject: Re: [BITX20] Digitally Controllable Heathkit Vacuum Tube Radio

On Tue, Dec 5, 2017 at 06:37 pm, Gordon Gibby wrote:

Using the bitx40 Raduino, I can fully tune (one any one band) the Heathkit SB-100 vacuum tube radio now.? ?In order to change to a different band you do two things:

Gordon. Are the details of your work published anywhere? I'm about to try the same trick on my?old Swan-250C (single band) 6 meter rig. I'm debating whether or not to use Jack's basic VFO circuit & software with an added Si5351?board to provide the carrier oscillator and calibration function, or to just do it all with the Si5351. I'm particularly interested if you had any issues with drive levels or square wave filtering between the digital VFO and the tube radio.

Thanks!
--
John - WA2FZW

-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...

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?Created a fairly straightforward pcb to provide RFI / EMP protection for a Raduino driving a Heathkit.? ?The real advantage of vacuum tube gear is its inherent EMP hardening (verfied by published QST tests).? ?Much military gear is already hardened, and some groups of which I'm a part are working to harden some of their systems now that NK is so capable.

Two lines have to come out of the Raduino enclosure:? power and signal.

For my heathkit, signal is a 5MHz VFO signal, so I put a 10 MHz LPF (from a kit), and a diode back-to-back array designed to clamp at +1.8 and -1.8 volts; similar to what is used in some T/R circuity.? Also a gas discharge tube at the outside-world end.? ?

Power gets filtered with two capacitors, and protected with another gas discharge tube, a TVS diode, and a series diode to prevent those "oops" moments.? ?

This is to go into a hardened system for our local Emergency Operations Center, then I need to build one for myself as well.? ?

Howdy Gordon,

may I ask where your injecting your heterodyne signal from the Si5351a into the SB-100?? my guess would be at the common connector on the band switch, is this correct? if that is the case I had considered altering one of the wafer sections to indicate the band position, or perhaps adding a sensor to the shaft for that purpose. another wafer switch maybe with a resistor ladder??

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Yes, I got plenty of bare PCBs for Lotsa Clocks.

And we are waiting for a report from Vince who got one of the first assembled units.

It has the 20 Pin SI part with extra address jumper for I2C.? This part is more expensive than the smaller 10 pin part, about $2.42.

So it can be run from Raduio with the 3 clock chip by selecting other address.

It has on board 3.3V regulator and level shifting.? So it runs stand alone on I2C connector.

Molex output with grounds next to each of the 8 outputs.

Email me for more info... I got about a half dozen other boards too!

73's and Keep Clockin,

Mike, WA6ISP

MotDog@...

?

So does Mike Hagen in this very group!

Vince.


On 01/09/2018 10:53 PM, freefuel@... wrote:

if you want 8 outputs this vendor has a board with the 8 output version
of the Si5351A chip
installed,

-Justin N2TOH

-- 
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID  "MotDog@..."
Mike@...