Gwen

Look again, I remember a menu setting in the stock firmware to designate using a paddle. I remember a few have fiddled some with those resistor values. Perhaps also check the entire path resistance,? after finding the setting.

Curt

Ok, I've replaced the BNC with an SO-239, and that is working a lot better. CW, though, is a problem. I had originally wired it for straight key, but decided to try wiring it for paddles instead. I added the 2.2k and 10k resistors, put them in the line as shown in the schematic, and connected them to the key socket. (I use W0EB's little breakout boards for this. Much easier to get at the thing.) Problem is, I STILL don't have paddle functionality. It's only operating in straight key mode.

I looked through everything, ran through the menus, and didn't find a place to change the hand key/paddle mode -- I gather that's in a different firmware set -- but I thought that it would work automatically once the voltage divider was in place. It's still only working with the sleeve connection for dah. I need to open it BACK up and start chasing things with the ol' multimeter, but if anyone can think of something specific to check, I'd appreciate it.

This is a v3 board, no mods. I hadn't gotten around to modifying anything since I thought I'd blown it up. If I MUST, I can operate it with a straight key, and maybe even a Cootie, but it seems very squirrelly with a Cootie -- noisy, lousy contact, that sort of thing, even right after cleaning the contacts. I hit them with Deoxit regularly and pull a piece of paper through the contacts to take off any corrosion or tarnish.

73,
Gwen, NG3P
Who has to stop fiddling with gear and practice CW more...L2 class on Monday!

OK, staring from a point of experience...

First serious and decent amps in the 100W and up class even if home built will
cost not less that 2-5$/watt.? There are big metal parts and expensive transistors
in many.

Most of the cheap "70W" ebay amps have not been seen as working, for long.?
They are still in need of box, likely a real heatsink (adequately sized), low pass
filters and plenty of spare Mosfets and some do not work at all wall above 20M.?
Caveat emptor.

I have built many of the EB series of amplifiers and they are good stable designs that?
generally perform to the limits of the devices used.? Comments like "CB amps" are
generally meaningless and better avoided.? I have seen those apnotes applied
to CB and some are junk and a few were well done.? Quality is often a builder
thing rather than application.? All of the amp modules require a Low pass filter(s)?
and will be likely switched with relays or mechanically.

One last thing what you put in had better be good as 10x that will reflect
all of the flaws in you signal and more people will hear them and comment.
if that is not clear, garbage in, means garbage out.

The biggest issue for those amps are the transistors for them are scarce and often?
very expensive.? I built them as I already had the devices and last look MRF454s
are over 100$ a pair for real ones.

EB63, basic simple amp, the down side is the diode current alone will be high
and that establishes the bias.? Efficiency when built right is over 50% however
at 160M or over 10M the design is not optimal, that's hard to do over a decade
of frequency range.? However with a good low pass filter and clean input the
result is excellent but the transistors used are costly and it can be intolerent
[unstable] of random substitutions.?

AN762? is a later design that uses a 723 voltage regulator to do a precision bias?
and that is an improvement.??The deal is its excellent and not a simple build
plus the devices are near extinct, unless treasure is expended.? Most will
choke at the cost of the machined copper heat spreader alone.

An779 20W amplifer for a SSB transceiver, excellent amp with good efficiency
and low IMD? output.

AN593 amplifier for 160W (28V use) and a version for 12V that does about 80W
SSB and its a good design but one has to pay attention to the mechanical details
or cooling suffers and for 12V use the power is limited.? Since it has the driver is
part of the design its not suited for more than a fraction of a watt input.? For the
80w (13.8V) version max power in would be around 125mW.? Both versions when
correctly adjusted offer very good IMD.? I've built the 28V version.

Others built include AN791 using MRF247 for 80W at 2m. and the datasheet? MRF492
circuit with bias for 6M and near 100W output.? MRF140 28V 160W amp for 6M,
MRF174 for 2M at 150W, and?a utv8100B amp for 60W (with 5W FT817 drive) at 432.

For VHF and UHF I've built far more but there I do use more power but at HF?
I tend to build to the 4-5W level and rely on either my 100W radio if more is
needed or one of several amps that include the EB63, Wa2EBY,?and a
design that is similar to the EB63 with active bias.


Allison

Bill

On the Dentron, see if it uses a narrowband matching circuit, although that would also result in output power varying appreciably across the band. If you have a nearby RBN listener as I do, it may let you preceive the 40m harmonic level. My local RBN showed a simultaneous 14 MHz output when I used my hw16 on 15m, that I successfully adjusted. That's a sure problem feeding my triband yagi.

The nice kit being sold by N8DAH nicely addresses ubitx harmonics, last I heard in every tested ubitx by our club. It does not cure ssb upper band spurious on 15, 12 and 10m. (I am skeptical whether arrl lab knew to look for these in v5 testing).

Those single and few band rigs can incorporate narrower filters, making compliance easier.

Curt

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I have the other similar amp, AN762, that I got in the late 90's. I have the amp built up and mounted on a monster heat sink, with a supporting case ready, and just have to craft filters and bandswitching. A kit for filters is almost done - .

As usual, takes a while to finish multiple things....
John K0JD
Milwaukee, WI

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Asher, the 811A amp that I built when I was a kid used more like 2000 V; ? In the coming year I hope to refurbish it.?

The KL203 is a tabu in the ham community. Don't even think to add in parallel or replace C14 with a 500V 1000pf.

I’m replacing a bad pl259 connector on my Gap Antenna with a BNC crimp connector and I’m having a problem getting the various coax measurements like how far back to cut the outer jacket, the exposed braid, etc.?
So if anyone can direct me to a good assembly tutorial I would really appreciate it.?

Regards,
?Guy WB7SZI?

I have a uBITX V5 with the CEC v1.2 fw and installed a RTL SDR dongle as mentioned on de CEC blog.
Everything works only the RX frequenty on SDR is not the same as on the radio itself.

So RX on SDR console is for example 14.138MHz, when I switch back to the uBITX I have to tune to 14.1395 (which is the actual freq)

Is it possible to adjust that somewhere?

73 Werner pa3gyv

Like Jerry said, it’s definitely a frees-up of the arduino. I have the same issue when connecting the arduino to my computer (for cat control) and doing things to fast.?

Easiest way for you is to swap the arduino with a fresh firmware.?

73 Werner pa3gyv?

Thanks all for help! The biggest problem was RF getting back into the radio. The dummy was to close to the radio.?

Have to sort out one more thing, the input for my souncard for digital radio is parallel to the mic. So when the radio is transmitting both pc line out and mic are open. Easiest way is to disconnect the mic but I’m not born easy lol.

73

Gus,

If the display freezes up that means the Nano has gone off the rails for some reason.

First, make sure that the 5v supply on the Raduino coming out of the LM7805 is?
a good solid 5v when it fails.

Next, I'd try removing the Raduino from the radio, then power up the Raduino by
plugging it into a computer's USB port to feed it 5 volts.
See if it works better that way.
Even though it is not longer connected to the radio, the Raduino's display and encoder?
should work pretty much as they do when it is connected.

If it still doesn't work, then probe the encoder push button with a voltmeter.
You should see around 5v on the wire from the encoder switch into the Raduino
when the button is not pushed, and around 0v when the button is pushed.

Perhaps some other input into the Nano is getting sensed, and the firmware
in the Nano is waiting for it to be released?
Make sure the morse code key is wired up as described in the instructions,
and carefully check all the other wires into the Raduino.

But my best guess is that you have a defective or blown Nano that needs to be replaced.
If you have a Raduino that's only a year or so old, it will have a socketed Nano.
The Nano's are available on the web for about $3.
Not a bad idea to buy more than one, as they are easy to blow.
And easy to find other uses for once you learn a little bit of programming in the the Arduino environment.

If you do this,? be sure to buy one that has the header pins not yet soldered in place:
? ??
To have it fit into the Raduino socket, the pins will have to be installed on the "wrong" side of the nano.
You will also have to program the nano over a USB cable using the Arduino environment
on a host computer with firmware appropriate for the uBitx.

Perhaps others in the forum will have other suggestions for things to try
before you go to the trouble of replacing the Nano.
??
Jerry, KE7ER

My uBitx seems to be working after some prior difficulties (that some of you may recall). When I power on the radio, the VFO (as well as the push function on the VFO knob) seems to function properly for about 10-20 seconds, after which it just freezes and won't operate. Any ideas? Thanks in advance for any thoughts on this.

-Gus

Well Ashar

I plugged KL203 and not bad.? Not the best but works.? I need to mod KL203 to expand the power range; on 20m, it was good no issues.

Sajid

The AN762-140 should be a good amplifier, I think it was described so in the ARRL 2010 Handbook. It needs lowpass filters like those Communication Concepts sells. It seems not overly complex to build.

Correction. Main board and Radiuno