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Well, the work you guys are doing is incredible. In it’s difficulty I mean. ? It was much easier just to add a daughter board with the right sided relays! ?Minutes. ?

Yes, the board placement and routing could be better.
Design should be improved on v5.

Allison has spent months poking at uBitx's, and making careful measurements.
I have not.
I am curious what she sees with a stock uBitx, KT1,2,3 replaced with Axicom, no sockets.

Allison wrote:
... and Kees S21 show it,? the rising tail as frequency is increased showing?the frequency dependent coupling.

Can you tell me where to find that?
A search for "Kees S21" or "K5BCQ S21" mostly just finds your last post.
If 20,40 and 80 are clean, that's good enough for me on a $129 transceiver.
It may be years before most of us find reason to venture above 20m.

Looking back through this thread, I see many examples of measurements
that find the Axicom relays bring the uBitx harmonics into compliance with US regs at -43dBc.
Here's a few examples:
? ??/g/BITX20/message/60371
? ??/g/BITX20/message/61018
? ??/g/BITX20/message/60980

As Raj notes, they do have to be seated flat on the board, no sockets.

I can believe that some fail to come into compliance.
Could be a different flavor of Axicom relay, different installation of the relay,
other mods already hacked into the board, drive level, IRF510 quiescent current,
supply voltage, a different method of doing measurements, different frequencies
within each band, and who knows what else.
It's complicated.

On a QRP rig, close to -43dBc is close enough for most (but not all) of us.
At that point, harmonics on a 10W rig are down around 1/2 of a milliWatt.
On a compliant 1kW rig, the harmonics might be as much as 50 milliWatts.

If you want better than what the Axicom relays do, then running coax from the
uBitx final to some external box with LPF's is an option.? Or perhaps one of the
other LPF hacks to the uBitx board described in the forum.??


Next up: spur fix.

If Raj's L5,L7 replacement fix works well enough, that seems ideal (simple).
I'd probably try that first.
Be sure to use the specific shielded parts he recommends,?
standard issue surface mount inductors don't help.

Farhan's LPF where the 45mhz IF goes into the D1,D2 mixer looks good as well.

There has not been a lot of talk here about a 12mhz spur, but Farhan's 12mhz trap
and hack to the 45mhz IF amp is worth looking into if it is an issue.

Jerry, KE7ER

On Sat, Dec 29, 2018 at 01:21 PM, Bob Lunsford wrote:
I had a sudden thought... It does happen.

>>>Considering Allison's wrapping the relays to get some isolation,
if the relays are somewhat mirror-image connection-wise, what
about merely mounting the relays on the other side of the board?
This would give some isolation because of he ground plane of
the board and some lower risk of feeding the wrong signal to the
wrong location merely because of the distance increase.<<<

IT may help but if you really read everything.? ?The problem becomes obvious?
once the relays are out of the way.??

I repost the picture from the wiki...

Fix that and things get better.?

Allison

Hi,
My uBITx V4 with the Nextion 2.8" is running just fine except the S-Meter. I have attached a 5k potentiometer between GND and 5V and wired the middle contact to A7.
Enabled the S-Meter Checkbox, I can see valid ADC reedings in the simulate window of the uBITx Manager tool as well on the ADC readout on the Nextion Config / Read ADC page.

Is there a bug in the uBITx<>Nextion protocol?

73, Uwe, HB9FZG

Mike

Most of us were puzzled somewhere in putting the fine ubitx into the nice enclosure kit.

I am not sure why there are 2 places to plug in the mic. I used the 4 pin connector, and wired in an old speaker mic I had. Okay to use the supplied mic element and a button for ptt. Some have installed a 8 pin connector to match another rig they have.

Ubitx.com does have much info now on case integration.

Curt

First off, the electret mic/PTT combination share the ground or common wire.? The uBitx PTT is activated by pulling the input line down to the ground or common voltage.? The microphone is connected between the other wire and ground.? In the original HF Signals' supplied parts, that is connecting the "tip" of the 1/8" (3.5mm) plug to the positive of the electret mic and One side of the PTT to the "ring" connector.? The two common connections are connected to the "shield" of the plug.

I am not familiar with the Amateurradiokits case and front panel board, however it does have to connect to the uBitx board, and for the supplied mic and switch it should follow the above wiring.? Are you saying that the Amateurradiokits board comes with an XLR style socket?? I would assume that that would accommodate typical hand held mics used for both Ham and CB radios.? There are many wiring diagrams for those mics, so you would need to find the specifics for the mic you have to match to the combination that you have.

I assume that you have looked at the wireup instructions on the HF Signals web page:


If you have more questions, I would need to know where to find the wiring or schematics of the front panel board.? A quick look with Google did not bring it up.

Not even a little bit of snickering going on here!

73
Evan
AC9TU

REF:
OldEngineer:

Go into the wiki or back postings and look at a sample board that had been stripped
of the relays.

Short and simple, its a mess. Adding your proposed while it may help a few DB but the
problem and Kees S21 show it, the rising tail as frequency is increased showing
the frequency dependent coupling.

FYI Before stripping relays that board I did warp and ground the relays with copper foil.
it was a lot of effort for barely 3db improvement. Same for AXICOM relays. Shield under
that may or may not fix the board layout issue but accidental shorts are a problem
and contact blow by remains.

Rewiring as describes netted 10DB++ and the filters show more of their characteristic
curves as if they were not compromised. FYI the 7 pole filters are good design and work
but the wiring (unintended coupling) around them makes the look very poor.

Allison

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I had a sudden thought... It does happen.

Considering Allison's wrapping the relays to get some isolation,
if the relays are somewhat mirror-image connection-wise, what
about merely mounting the relays on the other side of the board?
This would give some isolation because of he ground plane of
the board and some lower risk of feeding the wrong signal to the
wrong location merely because of the distance increase.

Some may want to try this. Mounting the board would not be a
problem since the relays' height would be a decent distance
above the mounting box/chassis, anyway. The relays maybe
should not touch the mounting/box lest there is in increase in
microphonics risk. Some thought has to be put into this. However,
it seemed to me to be a big plus if only mounting the relays on
the other side of the board is tried. The necessary connections
may require rewiring the pick lines but the switched lines may
be right where they need to be, depending on the design of the
relays;

Bob — KK5R

--------------------------------------------

?OldEngineer:

Go into the wiki or back postings and look at a sample board that had been stripped
of the relays.

Short and simple, its a mess.? Adding your proposed while it may help a few DB but the?
problem and Kees S21 show it,? the rising tail as frequency is increased showing
the frequency dependent coupling.

FYI Before stripping relays that board I did warp and ground the relays with copper foil.
it was a lot of effort for barely 3db improvement.? Same for AXICOM relays.? Shield under
that may or may not fix the board layout issue but accidental shorts are a problem
and contact blow by remains.

Rewiring as describes netted 10DB++ and the filters show more of their characteristic
curves as if they were not compromised.? FYI the 7 pole filters are good design and work
but the wiring (unintended coupling) around them makes the look very poor.

Allison

Horse twice beaten (maybe more) and the problem remains.

Changing relays may "help" some.? ?The problem is the board layout.
IF you don't drive the radio hard to get full power it will be cleaner
and the harmonics measured may appear better.? It may even meet
the -43DBc US limit.? The relays helps in its being pushed harder
and does not meet.? However all testing at 80M or 40M and full
power says very unlikely to meet and the relay change may or
may not be enough.

Its that simple.? ?Its been in the wiki since September and well
understood before that.? ?All the wishful thinking and "mine doesn't"?
is dancing around that.? ?

Allison

Question from a really new Newby (first kit build). I have the main board of the uBitx v4 and all the connections to an Amateurradiokits case including the front panel PCB from ARK wired. My problem is: the XLR mic socket has 3 wires connected to it; the PTT MIC has 5 connections on it but the Electret mic has 2 solder pads and the PTT switch has 2 connections. How do these get wired together? Which plug should I use the XLR &/or the stereo? I've looked at all the sites I can think of to find a picture or instructions to no avail.
Thanks for any and all help and I can hear the snickers!
Mike, WU0G

Hi,

The advice is in the messages. Some of the advice is to change the relays and correct the excess harmonics. The other advice is it doesn't correct the harmonics. Still other advice is the harmonics are not out of the limits. It's your radio. Do what you think is best.

73,

Bill KU8H

--
bark less - wag more

Since we're on the subject, don't stop with your radio stuff.? I've recommended to most of my friends and relatives to start a death book.? This applies more to those of us in old houses and/or with property and/or animals but think about all the things it takes to keep your home running that probably aren't known to your spouse/partner/survivors.? Stuff like how to get the ancient boiler fired up in the fall or your well/drinking water system maintenance.? Don't overlook appliances, alarms, and electronics.? Not to mention care and feeding for any animals and even contact information for financial institutions.? It also helps to label things like the water shut off for the house and diagram your electrical system if you have multiple sub panels and disconnects.
--

--

Any advice on this??
--
73, Al - va3iaw

In my view Ebay is an efficient way. Who 'wins' the auction is usually another ham willing to restore or keep alive the old stuff. Leaving everything to the radio club may be an alternative, but not totally sure it is the best way. I would avoid flea markets for hams. It happened to me I refused to buy good pieces because they set the price too low.

Bob

Good approach,? although I confess to having a few rigs, including the hw16 I used in 1970 something. Yes good advice to not always be increasing in rigs. Enjoy them and pass them on sometimes.

We must also recognize the bitx and ubitx to be international in scope, my we are blessed by folk in India that make it happen. To some hams its their only rig. I fear when we flaunt too much affluence or knowledge here. Let's help everyone, everywhere enjoy the bitx and ubitx experience,? and not forget we come from diverse cultures here.

Happy 2019 to the bitx world.

Curt

REF:
"My friend updates his inventory of equipment yearly with prices from QRZ, eBay, etc. his XYL has a good starting point "

For a knowing person, wise about radio equipment and its value,
it can be a good investment. However, I have friends who would
handle it if something catastrophic happened. Otherwise, I am
busy "thinning the herd" and believe one good, simple working
system is wisest for me. However, as the old saying goes:
"Everyone's taste is in his own mouth."

Bob — KK5R

--------------------------------------------

It looks like electret. It should work, but don't expect to outperform the stock electret shipped with the ubitx.