Re: uBitX SSB transmit oscillations on 20m only
#ubitx
Bruce,
I dont know if you fixed this problem. Here are some ideas.
Try a shielded wire for microphone inside the enclosure. You MUST use shielded wire for the mic cable outside as it may pick up TX RF.
Solder a 1000pf cap across the socket.
Formula I followed in the 70s for mic mixers was to insulate the jack from chassis. You could screw on an acrylic sheet
piece to your panel and mount the mic jack on it.. but you need to enlarge the chassis hole so that the jack does not ground.
Raj
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At 28/07/2018, you wrote: First a correction. The distorted output is on 20m not 40m. Now that's embarrassing! A form of ham dyslexia perhaps?
Audio feedback? Although I had gone through all the bands with no distorted output, I have been mostly comparing 20m with 40m. Distortion-feedback on 20m, clean on 40m. I just went back through all the bands and noticed that I hear a little audio from my speaker as I go up the bands. 80m, 60m, and 40m are good with a clean signal on the 'scope, nothing from the speaker. 20m is badly distorted with feedback and garbled audio from the speaker. 17m and up (in frequency) clean signal but faint audio from the speaker.
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Re: hacking bitx40 for 20 metre
#bitx40
Fairly healthy rebuild wouldn¡¯t you say?
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has anybody hacked the bitx40 for 20 meter. i have not yet purchased a bitx40 . i only want one band, so ubitx is a bit ottp. But i prefer 20 m to 40 m what coils need rewinding and how many turns. What change to the raduino sketch.
terry gm4dso
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Re: Digital / Audio connector names?
Already answered : Search kf2510 (in this group and on ebay)
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hacking bitx40 for 20 metre
#bitx40
has anybody hacked the bitx40 for 20 meter. i have not yet purchased a bitx40 . i only want one band, so ubitx is a bit ottp. But i prefer 20 m to 40 m what coils need rewinding and how many turns. What change to the raduino sketch.
terry gm4dso
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Which model of Nextion are people using?
73
Ken VA3ABN
On Sun, Jul 29, 2018 at 6:32 AM, hirosmb <hirosmb@...> wrote: I bought it at eBay.
Spec:
// hiro, JJ1FXF
Hi All
Could someone possibly point me to a link to purchase the Nextion TFT and spec sheets?
73
Ken VA3ABN
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Re: End Fed antennas w/ uBITX
#ubitx
At the bottom of every message is a series of links, one of which 'mutes this topic' for the subscriber.
Ken
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On Jul 28, 2018, at 9:43 AM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:
If everyone had a means to hide certain threads when browsing the forum,
that should also work well enough. Unfortunately, that is not the case.
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Good to hear, Ken.
I got the 2.4¡± one but feel it¡¯s too small.
I¡¯m planning to buy a little bigger one.
// hiro, JJ1FXF
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Thanks Hiro, exactly what I was looking for.
73
Ken VA3ABN
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Thanks Hiro, exactly what I was looking for.
73
Ken VA3ABN
On Sun, Jul 29, 2018 at 6:32 AM, hirosmb <hirosmb@...> wrote: I bought it at eBay.
Spec:
// hiro, JJ1FXF
Hi All
Could someone possibly point me to a link to purchase the Nextion TFT and spec sheets?
73
Ken VA3ABN
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Michael, Now that you are on frequency you can adjust again the BFO. BFO frequency differs from unit to unit depending on the filter passband. If the pitch on receive is too low you should increase your BFO frequency, or lower it if the pitch is too high. From your IF shift required I guess your pitch is low. Play with BFO (carrier) frequency a little and see if you can get the sound you like. My RV1 setting is about 90% and I get 12 W on 80, 10 W on 40, 7 W on 20. Power out drops to 1.2W at 28.4 MHz. All those powers are CW, key down, not SSB, measured into a dummy load using the power meter on a MFJ antenna tuner. This has been discussed a lot and is the result of components used. You can try some of the hardware mods and find what works for you. Mine is stock, running at 12.8 V provided by a linear, 6 A capable power supply. On SSB my power was low, so I had to increase the microphone amplifier gain. I did not measure the carrier suppression, so I have no reference number for you. I hope this help. 73, Ion VA3NOI -- Ion VA3NOI
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Hi All
Could someone possibly point me to a link to purchase the Nextion TFT and spec sheets?
73
Ken VA3ABN
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Re: End Fed antennas w/ uBITX
#ubitx
I really fail to see a serious problem with this thread. Sure if ppl don't like a bit of controversy and vigorous discussion then by all means hide the thread but personally? I have learned more from this thread than any other I can remember in the bitx20 group.
Now Ill just have to build a couple efhw? antennas and and do some hands on testing.
Ian?
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Re: uBITx V3 Stuck in Transmit
#ubitx
If it is a continuos carrier the check for short of
blue wire. It should have 5V through
the 4.7K resistor.
Raj
At 29/07/2018, you wrote:
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Hello All
I have built my uBITX V3 into one of Sunil's [VU3SUA] metal boxs as per
instructions supplied.
I powered it on to test, and I see the raduino loads the software, but
then immediately it goes into CW transmit.
Well I was surprised, as I had taken note of the WARNING in section 3.3
"Wiring up the CW Key" and note that I indeed have the 4k7
pull-up resistor installed.
I have doubled checked all wiring, measured the resistor to make sure I
have the correct value, and cannot find anything wrong.
Has anyone else had a problem like his, and how did you fix it?
Anyone have good pointer to look at?
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Kind Regards
Rodger - ZL1RAH
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Re: Digital / Audio connector names?
They are Molex KK type and widely available through component dealers and eBay.They are 0.1" pitch.Hope this helps.Ian Reeve M0IDR
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Molex KK and on the Far East sites KF2510
Mike ZL1AXG
On 29/07/18 11:58 AM, Joel Moerkerk wrote:
Hi all,
having a great time with my ubitx, but in my hast to assemble with the shortest flying leads possible i was a little over enthusiastic and cut a little short. im wondering what the plugs are known as so as to order a couple of replacements.
Thanks for all the awesome info on this list!
cheers
Joel
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Re: uBITX HF transceiver and blue MBITX metal case.
Ian,
? ? ? ? Looks like you have the uBitx case from Sunil Lakhani VU3SUA / amatuerradiokits.in? Attached are the pix for wiring up the Ubitx and the additional boards in the Case. It is documented at various places by VU3SUA. I have downloaded all the pix and put it into a single folder and that should help you.
73
Sunil Sankaranarayanan VU2MTM
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uBITx V3 Stuck in Transmit
#ubitx
Hello All
I have built my uBITX V3 into one of Sunil's [VU3SUA] metal boxs as per instructions supplied.
I powered it on to test, and I see the raduino loads the software, but then immediately it goes into CW transmit.
Well I was surprised, as I had taken note of the WARNING in section 3.3 "Wiring up the CW Key" and note that I indeed have the 4k7 pull-up resistor installed.
I have doubled checked all wiring, measured the resistor to make sure I have the correct value, and cannot find anything wrong.
Has anyone else had a problem like his, and how did you fix it?
Anyone have good pointer to look at?
--
Kind Regards
Rodger - ZL1RAH
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From my old collection. For your information -
QUOTE-
One of the best audio amplifier on the market is the TDA2822, which works from 3 volts to 15 volts, when used as a bridge, pumps out a full 1 watt, and most of all, minimum components, just four electrolytics ! Very low noise and absolutely no mains hum.
? There are two versions, the TDA2822, and TDA2822M.
I have experimented with both and found that :
?The TDA2822 dip version, is more stable, and rugged, but if you feed more than 9 volts, it gets warm., and a protection circuit pops in and out for protection.
? The TDA2822M is the mini dip version. Does not get warm with 12 volts, but is less stable, and apparently has no good protection circuit. I have blown three ( they are some $3 to $4 for ten pieces from ebay) ! A simple accidental short circuit, and bang it goes. I accidentally touched the input with my soldering iron, with power on, and bang it went. This does not happens with the dip version.
? And, further to my last email, on ebay, you can also find kits with all parts and a PCB to construct an amplifier for as little as $6 shipped if one so desires to go that route.
? cheers, Graham ve3gtc - UNQUOTE
On Sun, Jul 29, 2018 at 7:29 AM, MAX <max@...> wrote: Thanks tom for being helpful. ? Regards. ? Max K 4 O D S. ? I've Never Lost the Wonder. ? Antique Electronics Site: ? ? From: [email protected] [mailto:[email protected]] On Behalf Of Tom, wb6b
Sent: Saturday, July 28, 2018 6:33 PM
To: [email protected]
Subject: Re: [BITX20] Audio chip burn out. ? Here are a couple of links that summarize the audio chip issues.
Putting a resistor in series with the headphone jack can protect against the chip being shorted out. In my case I put two series resistors, one for the right and one for the left channel on the headphone jack. That way I can use either mono or stereo speakers and headphones with the uBITX.
Tom, wb6b
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Re: [VK3 Event] Bring your Bitx/uBitx - Melbourne QRP by the Bay 28 July
A few pics of the 'event', my first time at Chelsea Beach (about 20min drive Sth of Melbourne central) Peter VK3YE and uBITX on 40M, EFHW antenna.   ? Shot along the beachside table 
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Raj vu2zap
Ion Petroianu, VA3NOI