I have been operating FT8 with the uBITX and in some situations would like to use it to drive my linear. Problem is that It puts out more power than I want going into the linear. On 20m last night I fired up the linear and was putting out 100 watts. Way more than I need for this mode so I immediately went back to barefoot. The linear has only High and Low settings (I was using low of course). Is there a simple way to vary (lower) the output power? A new knob on the front panel would be ideal. HI

?

73, Dennis

W7DRW

I believe 13.8 is considered the upper limit for the uBITX main board.? It should work fine as-is, but I wouldn't push it any hotter.
If you wanted to be extra careful, you may want to put a 12v voltage regulator like a LM7812 inline with the main board's power.? The PA power line (brown wire, IIRC) can run off the higher voltage just fine and may get you a bit more power even.

开云体育

The simple answer is yes it can except you would need to change the code to switch it inline when on 160.

Ashhar,

I have a version 3 board (only have it for a couple weeks) with stock software.

Thanks,
73, Dennis
W7DRW

followup and notes:

First this is not a problem for any band if one is using CW.? The method of generation for CW?
makes this a non issue.? So CW on any band is fine.

The LO for the 45 mhz conversion to output frequency is high side already.? Low side would
be a real mess as it would fall into the passband when the VFO got to about 29mhz
(20M band).? Lets not go there.

FYI: Sideband inversion (USB//LSB) is done at the second conversion to 12mhz
by using a 33 or 57mhz output from the oscillator.? This has no effect on the issue.
Where the BFO is has little issue with this as well.

Things that can help for those that want 15, 12, 10M? and that is external band pass filters.
That means relays and logic so for tx only there are four conditions.? 15,12 or 10m filter,
straight through depending on band or RX mode.??

Most tuners be there T or L types will not have enough "selectivity" as the generally run
at low Q and are not tuned to reduce spurs.? Also antennas used like G5RV and similar
radiate well in the mid 14-18mhz range where the spur is.? The game here is never let
it out of the box.

Keeping your audio drive in the reasonable range sounds good but how to you know you
are or are not?? The question is not is it there but is it excessive.

A mod to put narrow band pass filters for 15,12 and 10 would work with added switching
as they are needed only for TX.? Their insertion loss will aggravate the existing problem
of low power and would need more gain to overcome.

An approach is moving the first IF to 60mhz or higher.? Its way out as the first?IF has to
work there and 3904s are inadequate and available inexpensive filters may be an
additional problem. An LC filter is lossy and requires tuning and this would
complicate the no factory tuning feature of uBitx.??

It all goes back to the general problem of DBMs being easy and very good but
also a conundrum? in three ports.? Any of the three post is and input or an output and?
while we put two signals in for a third out that third one is present inside and can then?
mix with the other two to get a whole new family of signals.? Only one solution is
Pick or avoid those unwanted signals or a band pass filter to only allow the desired
ones.? Seems to prove Nyquist was right.


Allison

Anxious to join the movement. One caution or stumbling block I've found is the difficulty of adapting code for various display sizes.

I've only had limited luck rescaling the figures, but haven't learned enough to convert one.

I have a 5" version but plan to get the enhanced smaller one like Ian's.

I don't understand how someone has connected it to the ubitx.

I just read that it can be used without the Nextion library, with just Arduino code. Going to try that way to start.

Any help appreciated. I'm now a very old, very slow learner compared to my hotshot days!
73 Bo W4GHV since '54

Jerry,

Isn't the standard convention to use USB on 20m and up? At least that's
how I have done it since the 60's. Wouldn't this help with the spurs?

tim ab0wr

On Sat, 02 Jun 2018 02:43:36 -0700
"Jerry Gaffke via Groups.Io" <jgaffke@...> wrote:

Move to a high side VFO.
Can be done by just switching to USB mode.

I believe all firmware to date uses a low side vfo, at 45mhz -
OperatingFrequency. when in LSB mode.
This was done so that the BFO was low side, to avoid interference
with Nano oscillators. If that's an issue, I think it is easily tamed.

Jerry

I'm wondering if someone would like to put an upgrade kit together when ready? I'd be willing to pay for this.

Allison,

excuse the noob question. I have a handful of 2n2222's in my box. Are these anywhere near the same as your 2n222A?

Thanks,
Dave

Solved it yesterday. On my Raspberry pi ?at least. Trying on my PC today.

Using flrig along with fldigi. Even tho the version on the pi doesn't have the flrig option. I clicked the rigcat option and it worked great.

I read that hamlib needed 2 stop bits but the code in the two firmware versions I have use only 1. I changed and recompiled but saw no change.

Anxious to start using instead of tinkering and troubleshooting. ? Bo W4GHV?

Is the 7805 getting hotter than it did when things worked?

Carefully measure the voltage of the 5v pin out of the 7805 to ground.
The 5v pin is on the top of the 7805, the pin nearest the blue contrast pot.
You can use one of the Raduino corner mounting holes as ground.
Do you see 5v there?? (I would guess you do.)

Any idea what happened to the rig between when it did work and when it didn't work?

There's a bunch of unused wires hanging off of the Raduino, did they possibly brush against
random points o the main board?? (Best to tape the ends of those wires up, or remove
those wires entirely by extracting the pins from the connector).


Using a shortwave receiver in SSB mode (not AM), put the antenna near the DDS wire from Raduino to main board.
With stock firmware, I believe the VFO is around 12-7.2 = 4.8mhz.
But with Allards improved firmware, it may be there, or have moved to 12+7.2 = 19.2mhz.
Can you hear that VFO carrier?? ? It's probably within 100khz of the stated frequency.
My guess is that you won't hear the VFO.


My best guess:??
A loose wire end from a Raduino connector brushed against 12v on the main board
and fried the Nano on the Raduino.? So you won't find that VFO using the SW receiver.
You could fix this by clipping out the old Nano and replacing it with one you buy locally.
Or you could replace the entire Raduino.

Do you have a scope?

Jerry

On Sat, Jun 2, 2018 at 06:41 am, Hans Stoll wrote:

Where to find the stock firmware (for uBITX r3) source code?

Oh sorry, found it:

Runs with r3 as well?

Where to find the stock firmware (for uBITX r3) source code?

The CEC firmware has a menu setting to turn off transmit??
Dan, W2DLC?

Thanx, Dan.? Yeah, I am drinking from the BITX firehose right now, having just jumped into this.? 73 Bob W8RMV

Disconnect the power to the PA and only feed the logic as a kiss solution.
--
Ad, PE1GIJ