Re: BitX HW-16: full break-in high power ri
Tom, You need to poke around a bit further on qrpkits.com ? ?? Schematic is in that first assembly manual listed. Second paragraph here mentions it plus a couple other options with regard to TR switches: ? ?? For single band use, Kang's TR switch is very simple: ? ?? /g/BITX20/topic/32744828But the inductor and cap must be series resonant at the freq of use, so won't work on the multiband uBitx. All of these T/R switching schemes have been around for decades. Jerry, KE7ER
On Sat, Sep 7, 2019 at 12:36 AM, Tom, wb6b wrote:
On Fri, Sep 6, 2019 at 10:51 PM, Ashhar Farhan wrote:
look for the bitx20a manual. It has a Tayloe T/R switching system
Hi,
I found some reviews of the bitx20a. Did not find a schematic, yet. However, I found this CW transceiver designed by Dan Tayloe that has a couple of mosfets to cut off the RF to the receiver section when transmitting.?
Is this similar to what you are referring to with the bitx20a design?
Tom, wb6b
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SolderSmoke Podcast 213 WE'RE BACK!
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Re: BitX HW-16: full break-in high power ri
Same here Tom. I lived near Huntsville when I was first licensed, WN4CCA. I sent off for a NASA technical bulletin ¨C ¡°Telemetry¡±. Latest in high tech. Interviewed at IBM Huntsville, they showed me their navigation system comprising three microprocessors ¡°voters¡± and an analog ¡°patch panel¡± navigation computer. I was hooked! ? 73 de KX4TD, Jim ?
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From: [email protected] <[email protected]> On Behalf Of Tom, wb6b
Sent: Saturday, September 7, 2019 3:52 AM
To: [email protected]
Subject: Re: [BITX20] BitX HW-16: full break-in high power ri ? On Fri, Sep 6, 2019 at 11:12 PM, Thomas Sharka wrote:
Cool site. Fun to look once again, in the context of the era of Heathkit kits and the early space race technology, the electronic designs I poured over learning electronics design.?
Then think of now, when microprocessors have almost replaced transistors as the fundamental unit of designs. Thinking about what a big deal Ham TV was. Now you have a portable wireless TV camera and video screen in your pocket. And you can talk on it and read the news, too boot.
Tom, wb6b
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Eric,
i have a couple of display protection boards left when you do your JackAl display
de
n2aie
vince
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I would appreciate assistance with the 40 please.
After triple checking connections, I fired up. The display was blocks which adjusted with the pot on the Rad board. It was drawing 140ma on idle initially, but seems to have dropped back to 70ma after having been on for a while.
There is a soft hiss on the speaker, but no signals on receive. Put the sig gen near on 7.1, but nothing when tuning, although there was a slight noise around 40 megs when I tuned around with the sig gen. Makes a clack clack noise while tuning which I suppose is the Rad incrementing. Bizarrely, moving the tuning control near full deflection either way starts the freq counter counting on at about 5 KC¡¯s/sec, such that it will count up to 7.5 and back to 6.9 the other way. Tuning control is very sensitive.
Any suggestions of tests would be appreciated. Wondering if I¡¯m just unlucky with a duff DDS. I have a scope and sig gen.
Roger, M0TJK
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Re: BitX HW-16: full break-in high power ri
On Fri, Sep 6, 2019 at 11:12 PM, Thomas Sharka wrote:
https://www.vintage-radio.info/heathkit/
Cool site. Fun to look once again, in the context of the era of Heathkit kits and the early space race technology, the electronic designs I poured over learning electronics design.? Then think of now, when microprocessors have almost replaced transistors as the fundamental unit of designs. Thinking about what a big deal Ham TV was. Now you have a portable wireless TV camera and video screen in your pocket. And you can talk on it and read the news, too boot. Tom, wb6b
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Re: BitX HW-16: full break-in high power ri
On Fri, Sep 6, 2019 at 10:51 PM, Ashhar Farhan wrote:
look for the bitx20a manual. It has a Tayloe T/R switching system
Hi, I found some reviews of the bitx20a. Did not find a schematic, yet. However, I found this CW transceiver designed by Dan Tayloe that has a couple of mosfets to cut off the RF to the receiver section when transmitting.? Is this similar to what you are referring to with the bitx20a design? Tom, wb6b
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Re: BitX HW-16: full break-in high power ri
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Re: BitX HW-16: full break-in high power ri
If you guys can locate, look for the bitx20a manual. It has a Tayloe T/R switching system. The other mod will be to keep the lpf relays powered up. The heaviest lifting is what we can do to avoid the t/r thump that results from charge on the rx IF amps that take time to discharge. - f
On Sat 7 Sep, 2019, 10:12 AM Tom, wb6b, < wb6b@...> wrote: On Fri, Sep 6, 2019 at 06:24 PM, Curt wrote:
my novice hw16 still lives
Interesting, I was looking around at sites that featured old Heathkit photos and product information. Found this link. Looks like someone is reviving Heathkit in Santa Cruz California. Maybe a nostalgic Dot Com millionaire? Much better than when Zenith was slapping the Heathkit name on cheap consumer products.
Tom, wb6b
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Re: BitX HW-16: full break-in high power ri
On Fri, Sep 6, 2019 at 06:24 PM, Curt wrote:
my novice hw16 still lives
Interesting, I was looking around at sites that featured old Heathkit photos and product information. Found this link. Looks like someone is reviving Heathkit in Santa Cruz California. Maybe a nostalgic Dot Com millionaire? Much better than when Zenith was slapping the Heathkit name on cheap consumer products. Tom, wb6b
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In my experience,? yes.? I haven't used Eneloops, but IKEA Ladda (supposedly rebadged Eneloops) and Amazon rechargeable AA will power it for a short time, but quickly go too low, resulting in flickering display, and then strange operations, followed by shut down.? ?Tempted to replace with a larger tray to use more AA to solve the?problem,? but haven't yet. AA alkaline run it for quite a few hours, however.?
-Josh W0ODJ?
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Re: BitX HW-16: full break-in high power ri
Lets see, the ubitx was advanced because many inexpensive rigs only do cw. Funny thing I mostly have done cw with the ubitx, but the early qsos were ssb.
I imagine somewhere there is a ubitx that does qsk, more likely a homebrew one. seems like a bit of work. BTW, study the qsk in some modern rig. especially the k2 100w PA to see how it gets the high negative voltage bias.?
Funny thing my novice hw16 still lives. The pfr3 I have pretty much does the same thing.
I did build a solid state xtal transmtter and used it with my tubed hr20.
73 curt
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Hi Rob,
No problems.
Ok for the regulator, that should work just fine.
Regarding the place to insert the Teensy, here are my thoughts: If you have an AGC then before the volume control as you mentioned should be just fine.
But if you don't, you may have significant variations in signal levels.? If placed after the volume control at least you apply some level control manually. Just a thought.
Also I would not worry about impedance matching until you test it. Just make sure it is AC coupled through capacitors.
For the serial part: in the Nano the USB chip's serial lines are connected via 1K Ohm resistors to the D0 and D1 lines. So you can hook up a TTL serial line there but you have to be mindful of the pull-up effect of the USB chip.
You can hook up the Teensy's RX and TX lines directly to the TX (D1) and RX (D0) lines (respectively) of the Nano since the Teensy 3.2 is 5v tolerant on its digital pins (which are shared with serial 1, 2 and 3). You may have to insert a 3.3V to 5V level converter for the Teensy's TX to the Nano's RX as the level may be on the low side of the specs for the Nano, but most of the time it just works.? If you have an oscilloscope it is easy to see what the levels are when sending serial data.
But, keep in mind that as long as the Teensy is connected to the D0/D1 Nano lines it will prevent communicating to the Nano via the USB port (like for programming). Best would be a switch to disconnect at least the TX line from the Teensy or better both TX and RX just to make sure, although just powering down the Teensy may also do the trick (hoping all lines go to high impedance then).
So I would start simple and add extra hardware if you run into issues.
I like the idea of using the Teensy for microphone compression. Please share your results when you get it working.
All the best,
73, John
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My new site adress :
the old ?was hacked ... and I lost the links ...
73 from py2ohh miguel
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Re: UBitx v5 Not Saving Calibration or BFO adjustments with CEC v 1.20 Nextion
Can you verify that after you get the message that the setting has been saved that you completely power down the Raduino (disconnect any USB cable and power down the board)??
The new value does not come into play until the unit is restarted from power off.? If you try to go back into the calibration mode directly, the values are rest to original, and you need to start over.??I figured this out the hard way using the memory manager.? Every time I updated a value, nothing seemed to change.? One time I ran out of time, shut it all down and then the next day powered up and found the values as I had set them.
Over all the process using Memory Manager is to make a change by reading the Raduino, decoding, changing, encoding and then writing to the Nano.? Power cycle everything including disconnecting the USB cable.? Verify, and go back and make another change.? This is time consuming, however you can save results on each try so you can go back to previous values.
I have not tried it, however a process of using the built in calibration, power cycling, then use the Memory Manager to save and see the new value.? This would be a way to get close, then make small changes to fine tune.
Above are my experiences and may be different from your own.
Use the above at your own risk.
73
Evan
AC9TU?
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Re: BitX HW-16: full break-in high power ri
Well, I could probably hijack the front end of the HW 100 and use it for exactly that purpose!
On Sep 6, 2019, at 17:19, Tom, wb6b < wb6b@...> wrote:
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On Fri, Sep 6, 2019 at 09:33 AM, Gordon Gibby wrote:
full break in HW 16
Brings back memory's of when I was first interested in Ham radio. The description of that radio/transmitter with dual conversion and crystal filters was something that made me want that rig. I did not become a Ham until much later when I hooked up a down converter
to a Radio Shack general coverage shortwave receiver and started following a group of Hams, on 2 meters (I had to slope detect), that would meet after work at a near by Denny's restaurant. I became interested in joining in, they were frequently discussing
interesting radio/technical things, so I contacted (by mail) one of the Hams, he lent me some more gear, I studied, got my tech license, and could join in of the work commute and Denny's.
Back to full break in mode. Tubes are still popular in the audio circles. Wonder if it would be possible (or valid) to create a stand alone tube RF pre-amplifier for receivers that would be bullet proof against (at least in terms of not burning out) being attached
to a coax line while a transmitter is powered up on the same coax. This could be great for near by lightning strikes, too.?
Then you could put a tee connector in your coax to directly connect to the vacuum tube pre-amp.
To some extent this tube pre-amp may be sold more on the?nostalgia of the gold old tube days. And unfortunately some marketers may start selling it on the claim that if gives your radio the much improved "tube" sound quality. But it might be a cool idea. Especially
if the tube sticks?prominently out of the top of the box, so you can see the red filament glow, and maybe a ring of blue LEDs at the base to add to the cool tube effect.
Joking aside, it may possible there could be a place for a vacuum tube in RF front ends.?
Tom, wb6b
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John,
Thank you very much for the very thorough reply.? Mostly (!) very encouraging, as I think this will save me a lot of thinking and worrying about ground loops in my RX audio and transformers and high-impedance buffers and the list goes on... I will try just putting the Teensy/Audio Board combo into the receive audio path, and call it good (my thought is, that I should already have sufficient DC blocking in the form of the Audio Board's built-in blocking capacitors on the Line-In/Out lines, from what I can see on the schematic).? Not sure if I need any other resistors for impedance matching or what not... I may just hook it up between the preamp and volume control, and cross my fingers...
I do have a decently beefy heatsink on my Raduino 5v regulator (had to bend the regulator IC "outboard", and then also bend a couple of the heatsink fins, to deconflict from the coils on the uBITX board).? But, I will try to implement a separate 5V supply for the Teensy, and add some additional filtering.?
I'll have to think about the D0/D1 thing with the TTL logic... so the way I read your description, D0/D1 and the USB are really not "interchangeable", rather they just happen to be linked to each other?? Is that the case?? I know that on Teensy, Serial and USB Serial are separate, but I thought that on Nano they are the same. Are you suggesting a pulldown resistor on D1?
Thanks,
Rob
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Hello Rob,
In my experience ground loops on transceiver to CPU based units are only an issue in TX when using "longer" wires.
For reference I used a second Arduino Nano mounted inside the uBitx and all signal cables not on the board, that is that are wired to other parts of the unit, are shielded audio cables (microphone type, 2mm or so diameter cables).
I used the Nano to inject an audio signal into the audio (after low pass filtering) for my auto tuner and no audio harmonics or hum was audible on another receiver in the SSB passband.
I also used an analog input connected to the microphone input as a VOX detector and again I can't hear anything on another radio at normal volume.
In RX it should not be an issue in any case if your device is mounted inside or connected via short cables to the unit.
I would use a separate supply voltage regulator for two reasons: the load on the existing regulator would be increased significantly requiring a good heatsink and this gives you the opportunity to ensure a good filtering between the Raduino and the Teensy supply and prevent any feedback/bleed through that way. It is what I did in my rig.
Regarding the usage of the Teensy USB that is a good idea. Just a reminder that some (most?) Nanos keep? the USB chip powered up when supplied from the internal supply (that is even if the Nano's USB is not connected) and therefore inject a TTL logical zero (+5VDC) when idle. Therefore you need to make sure you pull the digital line D1 (Rx) to a low enough voltage to ensure you get a solid TTL logical one (0VDC) when communicating with the Teensy.
See an example of that issue on this post (and the previous posts in the thread): /g/BITX20/message/66289
Hope that helps.
All the best,
73, John? (VK2ETA)
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Re: BitX HW-16: full break-in high power ri
On Fri, Sep 6, 2019 at 09:33 AM, Gordon Gibby wrote:
full break in HW 16
Brings back memory's of when I was first interested in Ham radio. The description of that radio/transmitter with dual conversion and crystal filters was something that made me want that rig. I did not become a Ham until much later when I hooked up a down converter to a Radio Shack general coverage shortwave receiver and started following a group of Hams, on 2 meters (I had to slope detect), that would meet after work at a near by Denny's restaurant. I became interested in joining in, they were frequently discussing interesting radio/technical things, so I contacted (by mail) one of the Hams, he lent me some more gear, I studied, got my tech license, and could join in of the work commute and Denny's. Back to full break in mode. Tubes are still popular in the audio circles. Wonder if it would be possible (or valid) to create a stand alone tube RF pre-amplifier for receivers that would be bullet proof against (at least in terms of not burning out) being attached to a coax line while a transmitter is powered up on the same coax. This could be great for near by lightning strikes, too.? Then you could put a tee connector in your coax to directly connect to the vacuum tube pre-amp. To some extent this tube pre-amp may be sold more on the?nostalgia of the gold old tube days. And unfortunately some marketers may start selling it on the claim that if gives your radio the much improved "tube" sound quality. But it might be a cool idea. Especially if the tube sticks?prominently out of the top of the box, so you can see the red filament glow, and maybe a ring of blue LEDs at the base to add to the cool tube effect. Joking aside, it may possible there could be a place for a vacuum tube in RF front ends.? Tom, wb6b
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Relay Board Mod for V3/V4 are in!
All pre-orders have been shipped and I have 12 kits left
More will be ordered as time goes on so if they are sold out I will have more coming.
I will also have a digital interface coming soon as well watch for it in the next two weeks.
Attached are the instructions from Gordon for those that can not get them via the sites account orders page due to errors my host has been giving on the site.
73
--
David
?N8DAH
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Jim Willis
Vince N2AIE
N8DAH