Topics

ubitx v5 receive problem

howard winwood G4GPF
 

just completed my ubitx v5 built into a ready made case, everything went together as expected, on switch on, nothing from speaker but headphones ok. found a short across the speaker terminals on the front panel circuit board (my fault!).
receive sounds very noisy, when a long wire is connected (not a proper antenna yet....) I get a massive increase in noise, very hard to distinguish stations even with volume control turned down. Also find it difficult to tune into a ssb contact.
I have an old home made tx/rx (about 40 years old) that picks up signals much better with almost no noise on same piece of wire than ubitx and tunes into ssb signal very easily on its analogue vfo, compared to ubitx.
is this normal for ubitx or do I have a problem?
Ubitx is supposed to have a sensitive receiver but due to the high noise level does not seem as sensitive as my old rig who's arial input goes straight into a diode ring mixer.
anyone have any ideas please?

Curt
 

Howard

I don't have any v5 experience but sounds like your BFO calibration may be off. Note the positioning of this oscillator relative to the crystal filter determine what is heard, I imagine it is the issue. Instructions on bfo calibration are around, but use something provided for v5. It should sound nice when properly adjusted.

Your makeshift antenna should receive fine on lower bands, but may be insensitive on some higher bands.

Curt

howard winwood G4GPF
 

Thanks for that Curt, sounds logical, why did I not think of that!!!!
I would have thought that bfo would be something they set at factory, but obviously not. Frequency set up was spot on so didn't think to check bfo settings. Will have a play when I get a minute.
Thanks once again
G4GPF

On Sat, 2 Nov 2019, 15:30 Curt via Groups.Io, <wb8yyy=yahoo.com@groups.io> wrote:
Howard

I don't have any v5 experience but sounds like your BFO calibration may be off. Note the positioning of this oscillator relative to the crystal filter determine what is heard, I imagine it is the issue. Instructions on bfo calibration are around, but use something provided for v5. It should sound nice when properly adjusted.

Your makeshift antenna should receive fine on lower bands, but may be insensitive on some higher bands.

Curt

pd0zz@...
 

My 2 cents... Do you have a real strong MW radiostation near you? In that case it would be advisable to install a special filter onto the motherboard. Look at this small BCI-filter...
https://www.youtube.com/watch?v=fgQenFJOjr4

Furthermore a BFO tune-up as described by VK3YE is very advisable...
https://www.youtube.com/watch?v=sXJmAhpAjeI

Happy ubitx-ing!

Op 2-11-2019 om 15:40 schreef howard winwood:
just completed my ubitx v5 built into a ready made case, everything went together as expected, on switch on, nothing from speaker but headphones ok. found a short across the speaker terminals on the front panel circuit board (my fault!).
receive sounds very noisy, when a long wire is connected (not a proper antenna yet....) I get a massive increase in noise, very hard to distinguish stations even with volume control turned down. Also find it difficult to tune into a ssb contact.
I have an old home made tx/rx (about 40 years old) that picks up signals much better with almost no noise on same piece of wire than ubitx and tunes into ssb signal very easily on its analogue vfo, compared to ubitx.
is this normal for ubitx or do I have a problem?
Ubitx is supposed to have a sensitive receiver but due to the high noise level does not seem as sensitive as my old rig who's arial input goes straight into a diode ring mixer.
anyone have any ideas please?

Virusvrij. www.avast.com

pd0zz@...
 

Then there is the AGC, as built by VK3YE... https://www.youtube.com/watch?v=GdpOkjETtw8
Three enhancements, easy built, easy incorporated, and your uBITx V5 works like a far more expensive rig...

Happy ubitxinging

Op 2-11-2019 om 16:39 schreef howard winwood G4GPF:
Thanks for that Curt, sounds logical, why did I not think of that!!!!
I would have thought that bfo would be something they set at factory, but obviously not. Frequency set up was spot on so didn't think to check bfo settings. Will have a play when I get a minute.
Thanks once again
G4GPF

On Sat, 2 Nov 2019, 15:30 Curt via Groups.Io, <wb8yyy=yahoo.com@groups.io> wrote:
Howard

I don't have any v5 experience but sounds like your BFO calibration may be off. Note the positioning of this oscillator relative to the crystal filter determine what is heard, I imagine it is the issue. Instructions on bfo calibration are around, but use something provided for v5. It should sound nice when properly adjusted.

Your makeshift antenna should receive fine on lower bands, but may be insensitive on some higher bands.

Curt

Virusvrij. www.avast.com

howard winwood G4GPF
 

many thanks to all who replied, setting BFO did the trick (as I should have known!!!!).
background noise much suppressed and can pick u/tune into stations with ease and with good audio.
can now start on the various mods, age, cw filter, s meter etc.
Oh! and a decent antenna of course :-)
cheers everyone
G4GPF

On 2 Nov 2019, at 16:53, pd0zz@... wrote:

My 2 cents... Do you have a real strong MW radiostation near you? In that case it would be advisable to install a special filter onto the motherboard. Look at this small BCI-filter...
https://www.youtube.com/watch?v=fgQenFJOjr4

Furthermore a BFO tune-up as described by VK3YE is very advisable...
https://www.youtube.com/watch?v=sXJmAhpAjeI

Happy ubitx-ing!

Op 2-11-2019 om 15:40 schreef howard winwood:
just completed my ubitx v5 built into a ready made case, everything went together as expected, on switch on, nothing from speaker but headphones ok. found a short across the speaker terminals on the front panel circuit board (my fault!).
receive sounds very noisy, when a long wire is connected (not a proper antenna yet....) I get a massive increase in noise, very hard to distinguish stations even with volume control turned down. Also find it difficult to tune into a ssb contact.
I have an old home made tx/rx (about 40 years old) that picks up signals much better with almost no noise on same piece of wire than ubitx and tunes into ssb signal very easily on its analogue vfo, compared to ubitx.
is this normal for ubitx or do I have a problem?
Ubitx is supposed to have a sensitive receiver but due to the high noise level does not seem as sensitive as my old rig who's arial input goes straight into a diode ring mixer.
anyone have any ideas please?

Virusvrij. www.avast.com