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new uBitx question

newoldham
 

First post, excellent group, thanks all of you...

I have a new uBitx V5 - seems mostly functioning in the early stages here - but there are audio tones at various frequencies that persist with the antenna disconnected.

The pitch (frequency) of the tone moves up and down with the encoder.  I hear some CW and SSB conversations, some are great, others overlap with this tone.  It's on at least the 20 and 40m bands.

(Haven't done any transmitting yet, saving that for later...)

Ideas?  (I have not done the calibration - because some folks recommend it while many others say do NOT do it unless it's obviously required.)

Thanks!

Curt
 

Craig

I am not sure what is going on with those tones. Are you using a clean power supply made for amateur use? A pc type power supply could make interfering tones and add noise.

I would not worry with frequency calibration as quickly as bfo adjustment, as bfo does relate to signal clarity. Are you hearing ssb signals clearly? If so, enjoy receiving some signals before digging too deep.

Curt

iz oos
 

Seems from the description birdies or digital hash within the ubitx. Try a linear power supply, twist cabling inside the ubitx. Once connected to an external antenna the noise floor might bury these unwanted signals. If these are independent from the vfo it might come from the audio stage and maybe an audio rc low pass filter might help.


Il 03/mag/2019 18:24, "Curt via Groups.Io" <wb8yyy=yahoo.com@groups.io> ha scritto:
Craig

I am not sure what is going on with those tones. Are you using a clean power supply made for amateur use? A pc type power supply could make interfering tones and add noise.

I would not worry with frequency calibration as quickly as bfo adjustment, as bfo does relate to signal clarity. Are you hearing ssb signals clearly? If so, enjoy receiving some signals before digging too deep.

Curt

iz oos
 

I am a folk that never has tried to align the ubitx. I found it very close from being perfectly aligned.


Il 03/mag/2019 17:53, "Craig Wiencek via Groups.Io" <cwiencek=aol.com@groups.io> ha scritto:
First post, excellent group, thanks all of you...

I have a new uBitx V5 - seems mostly functioning in the early stages here - but there are audio tones at various frequencies that persist with the antenna disconnected.

The pitch (frequency) of the tone moves up and down with the encoder.  I hear some CW and SSB conversations, some are great, others overlap with this tone.  It's on at least the 20 and 40m bands.

(Haven't done any transmitting yet, saving that for later...)

Ideas?  (I have not done the calibration - because some folks recommend it while many others say do NOT do it unless it's obviously required.)

Thanks!

iz oos
 

If you transmit also without talking into a dummy load and see the spectrum on an sdr without the any antenna connected you can have an idea whether you need to align it. You can do it with a normal receiver tuning exactly on the carrier (zerobeat) and hearing your modulation.


Il 03/mag/2019 17:53, "Craig Wiencek via Groups.Io" <cwiencek=aol.com@groups.io> ha scritto:
First post, excellent group, thanks all of you...

I have a new uBitx V5 - seems mostly functioning in the early stages here - but there are audio tones at various frequencies that persist with the antenna disconnected.

The pitch (frequency) of the tone moves up and down with the encoder.  I hear some CW and SSB conversations, some are great, others overlap with this tone.  It's on at least the 20 and 40m bands.

(Haven't done any transmitting yet, saving that for later...)

Ideas?  (I have not done the calibration - because some folks recommend it while many others say do NOT do it unless it's obviously required.)

Thanks!

newoldham
 

Thanks everyone for the ideas and feedback - some much needed nicer weather this weekend led to yardwork instead of "playing" so I haven't had a chance to
get back to it - will update again soon - but wanted to let y'all know I appreciate the help.

K B 8 H B F

newoldham
 

Ok, back to it finally - tiny bit of new input:

Was able to tune in a local AM station - sounds decent - tuned BFO with that, for better or for worse, but in the end, it was already ALMOST ok, and now it is certainly "listenable."

The strong tones were NOT present near that particular station.

I take back what I said before, sometimes it disappears entirely if I unhook the antenna, other times, it stays.  Two different problems, I suspect.

On several bands (20/40/80), I hear some garbled ssb, it's never very clear - but it may never be English I'm hearing.  I know the bands aren't grand right now, and I'm not expecting to catch a lot of conversation - my sdr pretty much
confirms the few noises I hear.  But far too often - the annoying tone comes with the SSB - what is it that I'm hearing?

however - on 40m and less so 20m, i hear an absolute ton of CW - and it never has an interfering tone.  Clear and lots of it, I'm having fun getting back into it.  My main plan for this thing was CW anyway.  This pretty much confirms it's an artifact of the SSB decode process - no?

So to summarize...CW crystal clear - I have not transmitted yet - and SSB miserable, while broadcast AM is fine. 



Curt
 

Craig

overall its a different sounding receiver - without AGC there is minimal (but enough) gain available. 

based upon your description - I wonder if the BFO adjustment is way off.  Before concluding this, tune very slowly to see if you can get the SSB signals tuned in.  When the BFO is properly adjusted SSB should sound very nice. 

note AM signals are received as one of the sidebands - so not possible that AM can sound good but not SSB. 

Curt

Jeff Karpinski (N0KAI)
 

On Mon, May 13, 2019 at 10:10 AM, newoldham wrote:
On several bands (20/40/80), I hear some garbled ssb, it's never very clear - but it may never be English I'm hearing.
Are you sure that's not just local AM stations? My uBitx was completely unusable at first - all bands, all frequencies, all i heard was the 50KW KOA "blowtorch". More sane AM signals will definitely sound like garbled SSB. Why the uBitx doesn't come with a BCI filter by default is a real head scratcher.

Jeff Karpinski (N0KAI)
 

On Mon, May 13, 2019 at 10:26 AM, Sam Tedesco wrote:
Yes...sounds like you might be way off. If you tune to 7.076 on lsb, you should hear digital mode. If you hear it at 7.074, you're way off.
Not aware of any digital mode using LSB. 7.074 USB is FT8, 7.076 USB is JT65.

newoldham
 

Thanks, everyone - based on Curt's comment, there may be nothing to adjust - I'm just not picking anyone up / trees in the way / bad weather / bad timing whatever. 

I base this on the fact that AM radio is, in fact, crystal clear.  I think it could be a tiny bit better, but it's perfectly manageable.  I listened to the ball game for a while last night.  I didn't feel like something additional needed done.

So I'm down to the weird problem of a steady tone, that varies in frequency with the tuning knob, that magically seems to be on top of the SSB I'm listening to.  NOT ALL OF THEM - but many of them.  (By many, I mean, I've heard about ten total, none of them usable, 3 were garbled on their own, 7 had the tone on them....rough numbers, don't quote me!)

BUT - if AM is usable, then, all things considered, if the right person were transmitting at the right time, maybe I'd hear them.

Question:  can one of you compare CW "travel" with SSB?  The CW I'm picking up is roughly 400 miles from me, both south and to the east - would I then pickup SSB the same distance?  Or...no?  If so, I might end up coordinating with one of you for an assist!

Thanks again.

Martin Potter
 

newoldham wrote : "I base this on the fact that AM radio is, in fact, crystal clear."

What kind of antenna are you using? My own experience was that with a long-wire antenna there was lots of BC interference. (I am about 10 km from an AM broadcast transmitter site, with more of them slightly further away). When I switched to using a dipole for 40 m or my multi-band tuned vertical, all the broadcast interference disappeared.
73,
... Martin VE3OAT

newoldham
 

It's a 20m Dipole, not well-tuned!

Martin Potter
 

newoldham wrote : "It's a 20m Dipole, not well-tuned!"

Using any antenna tuned to an HF ham band helps to mitigate against the "invasion" of interference from nearby AM broadcast band signals. So with a 20m dipole you *should* be OK. Are you near an AM broadcast transmitter site? Do those carriers have modulation on them?

73,
... Martin VE3OAT

newoldham
 

Ok, more small progress - finally received good SSB signal, approximately 300 miles away, on 80m.  Very clear.  No tones.  So it CAN work from time to time!

There's been much mention of the low audio level - but I have continuous static.  At the very lowest level (knob almost to OFF) there is static/white noise.  To increase it for "manual audio gain" - I might increase the signals
I'm hearing, but it will increase the "white noise" as well, so in the end, plenty of signals are buried in my white noise.  Normal?  no?

We're getting there!

Thanks, everyone.