OK, we have a lot of misunderstanding here...? uBitx.

If the master osc is not set on frequency everything else is likely to be off frequency and work poorly.

The filter is ladder filter (not a Cohn) and like all ladderfilters due to the parallel caps are loaded to
the lower frequency.? so technically it is a filter of about 2.1Khz with a center frequency a of
11.9989mhz built with nominal 12mhz crystals.? ?From here out we call it a 12mhz filter as?
11.99989 is just longer! ;)

Also the default startup setting for the software uncalibrated is 11.995 (at least 1khz too low).

The IF filter 12mhz has a roughly 2.1khz pass band with the upper edge just below 12mhz
and the bottom ends around 11.997ish? Small errors in BFO placement (100hz) is enough to
impact audio quality both RX and TX.? ?FYI OSC-0 is the BFO.? ?In mine the magic number was
11.996750mhz.? NOTE: the BFO is not changed to change sideband.

ubitx changes sideband by flipping oscillator 1 between 33mhz and 57mhz with a small correction
for the 45mhz filter that is not at 45mhz but about 5-10khz lower.? ? If the calibration is off or not
done correctly these oscillators will be off for the 45mhz filter and sensitivity will suffer (if far enough off).

Now if the 25mhz crystal on the Raduino board is off and generally they will be its the master
oscillator for the whole game.? So the first thing is to get the "calibration" dialed in so when the
MPU/software commands xxx frequency you actually get it and the other two oscillators are also
where they should be.

Changing out the crystals in the filter can improve the filter but not likely solve the "tinny sound"
as that set will likely have a different offset for the BFO.? ?FYI changing the parallel capacitors?
will also move the filter center frequency and the bandwidth requiring BFO change.??
They are not SMT they are conventional leaded HC49U parts and easily desoldered without
art or rework station.

If the BFO is right the low end should cut off at about 200hz and the high end around 2300hz.
That will not be tinny.

For an FYI: I included a image of the filter pass band while testing a personal mod to get?
to a wider band width (2.7khz) for better fidelity.? The ripples on the top of the pass band
are about 1.5db and not at all bad.? Even widened up the upper edge is barely 12mhz
(11.999985ish mhz).? Best sideband setting is 11.996685mhz for that filter.

Allison

Allison,

Thanks for all the suggestions!? Regarding your points:

• I do not have a star washer at the coax connector on the uBITX.? Nor do I have star washers under the mounting posts.? I'll give that a try.
• The matching box is this one:??
• There was no manual but the seller pointed me to this page:????I had 100ft of wire and wanted to use 40m-10m so I cut it in two to make a 39ft piece and a 61ft piece.? Both those lengths fit the 40m-10m range in the colorful table on that web page.? I started with the 39ft one at first then switched to the 61ft piece.
• The SWR is 1:1 at the desired frequency of 14.074 MHz.
• FYI, I'm in a townhouse.? The 25ft coax goes through the wall up into the attic and through the soffit to the matching box hidden under the eave (about 20 feet above ground).? The antenna wire runs under the eave south for about 13 feet, makes a 100 degree turn West and slopes downward with the end of the wire being about 10 feet above the ground.
• I had a ferrite on the power cable (you can almost see it in the photo) and tried building and inserting an air choke where the cable came out of the wall.? But if the coax is radiating that badly then the part beyond the air choke inside the wall 2 feet from the uBITX likely renders that moot.
• Would installing the air choke at the matching box be an option?? It would mean just a few inches of counterpoise/coax before the air choke.
• Would installing the 31 feet of extra wire on the counterpoise side help?

Thanks again!

73 Mike KK7ER

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Both if it’s easy??

IRF510 at 20M is not an issue or even working hard.?

I have several radios that really work on that band using that critter.
Bitx20 (V0) from the early years, uBitxV3,? Slopbucket 20 a Kd1JV design.? Never
minding a 10M radio that just got an upgrade from 2sc1307 to IRF510 (went from
5W to 12), a 160 to 10M amp using them (WA2EBY).? ?

Makes me ask what's wrong??

Allison

Terry, I did this. I also changed the PA FET for a RD15HVF1 because it worked a lot better on 20m than the IRF510. Info on both here:





--
Ryan Flowers - W7RLF

Sorry . brain fade.. invert the answer. Jack clearly had to set the BFO way Low to select USB so it would pass the Cohn filter which appears to have its passband low on 12.0000 but the issue still remains.. does the uBitx work correctly on a frequency that uses LSB such as 40m. I would guess not unless the firmware was utterly bullet proof Mil Spec. Re comment on LEon.. He may refuse the work as he deals only with 10 Meg IFs on the kits he sells. AND you would need to put the squeeze on someone you know with a a Hot air chip removal station for? SMD to remove all the affected crystals if the kit refuses to work properly on both sides of the IF. sometimes you may have to put up with something with limited functionality than the worst case outcome....

Jack it is not a problem - it's? FEATURE ! But if you were setting this up on a system which has to swap USB/LSB between 40 m and 20m, which yours will since you are uBitx ..? I suggest you need to check it? works on USB after you have done the cludge ie on 20m as it is clear to me you are talking LSB operation and thusly 40 or 80 for your fix.. I kind of see probos ahead,? unless the firmware is incredibly smart.??

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Its for the Real time clock. its not needed for now. if someone implements it in the firmware then it could be used.

hi guys,
what is the battery holder for on the nextion display ??
something we need ?

kevin rea
lancaster, calif.
k6rea

never mind.. i just received it today.

thanks,
kevin rea

Hi Again.

Would folks prefer the Pot to adgjust the ACG or the Jumpers as per Kees' boards?

I am in 2 minds about it,,,

73 Nick. VK4PLN

I was wondering how close those fires were.? The rule here if if you smell the smoke
its too close.? Take care.? Keep building!

Allison

Hi Allison,

I need to redeploy that antenna, I have the feed point at the same level as the far end and the wrong coax on it, so I know it's my fault it doesn't perform any better than it does. I threw it up in the air about 5 years ago and am just too lazy to take it down and do it right, I'm too busy building radios:-). This fall when the forest fire smoke clears I'll do it.

Joel
N6ALT

HI Again,
Just PCB boards. I am still designing them, and awaiting a new callsign too, so, I am hopin in the next week or so to get all my current board designs finalised and then place and order.

One more pic of the VK4PLN ND6T AGC board:


73 Nick VK4PLN

Hello, do you know if you have possibly shipped my unit?
Kevin Rea

Nick, would like to obtain 2-3 of your AGC PCB boards. If you are
planning a kit with parts, I can wait for that too. - Rich WB2GXM

Thanks all for sugestions....

Rich, This one is the same as Kees' in operation: RF
I was also wotking on an AF (VK3YE board) version for those who would prefer that...


73 Nick.

Nick, it is my understanding that Kees' AGC kit works of the RF (IF)
stage, whereas your kit works off the audio stage? Thanks - Rich
WB2GXM

Chuck,

I'd ague against more than an octave for another reason, pattern.?
That and for 12, 10M and 6M up antennas get small enough there are a
a whole other set?possible improvements.? ? ?I'd think if one can get a
monster wire up then several smaller antennas are possible.? A?
dipole for 6M in wire is maybe 115 inches, no excuses there.

Most do all wires tend to be among the greatest compromises.

FYI even though I have a LNR- quad (40/20/15/10) I don't use it on 15 or 10.
Its the goto for 40 and 20.? ?The K6STI loop on 10 is way better.? A larger
scaled version for 15 is very good.? I used a 6M scaled version in a tall oak
for FD and worked a lot stuff and had a 3 element beam to compare to.
Beam was better only when pointed that way.? ?Rest of the bands
(not VHF) if I want to work them I put up a monoband wire using
one favorite tree with a lanyard in it, poles, or green mil aluminum
pipe as a temporary tower.

Goes back to the first statement, pattern, you have to hear them first.

Allison