Yes, low output when speaking or whistling into mic.
Power wiring correct AFAIK.
RV 1 set at about 30% on arrival.? Adjusting to full CCW raises draw to about 1.6 A on PTT, with no change when using mic.? Reset back to about 30%.? Also, adjusting R136 has no effect.
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Re: The new uBITX boards are here
Hi, I am not Mr Farhan, am just a user and an advanced qrm maker. As for ' Problems: great carrier in SSB mode TX, more then modulation speech signal!' I believe you should move up or down the BFO as it seems to be within the bandwidth of the filter. Most probably your modulation would sound extremely muffled.
Il 18/lug/2018 10:27, "George via Groups.Io" <rx3arg= [email protected]> ha scritto: Dear Mr Farhan
As about me for several days I was asking for help as I've lost the original soft for scale and control of the Si5351. At last I've? find HEX file by KD8CEC and I am happy that it works!( Used XLoader).
But till this time did not find the original file and besides this I am not the Arduino specialist. A lot of words but no FILE and how to load it!
To my mind the R50 feed back of the Q70 should be raised to 820K to raise collector U from 1.8 to 6 V - not to over load it by strong signals.?
Problems: great carrier in SSB mode TX, more then modulation speech signal! What is it? to use only in reception mode?
The final 12 MHz filter is too wide and do not have 6/60 dB features, + some out of channel signals! But stii very simple and original transceiver not noisy with good sound! Some raising of the price of something 140-150 will not be too much for it. Best regards to you and your team 73! George UR4CRG/RX3ARG
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You might try Allard's mod to transmit CW, drive the top of C107 from 5v through a 4.7k resistor:
? ??
If that gives power to your dummy load, then the problem is back in the mike amp or mike.
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Is the low output with you talking into the mic? The carrier is suppressed in SSB as you know and almost no output is expected without modulation.
I had a mic go bad on mine after a month.? ?Found a replacement in an old portable phone.
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R136 with Bitx40!
1: Power connector all wires connected properly ?
2: RV1 at center ?
At 18-07-18, you wrote:
toggle quoted message
Show quoted text
Thank you for quick
reply.
Re-checked soldered correctly, and confirmed continuity to board
connector.
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1: Power connector all wires connected properly ?
2: RV1 at center ?
toggle quoted message
Show quoted text
At 18-07-18, you wrote: Thank you for quick reply.
Re-checked soldered correctly, and confirmed continuity to board connector.
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Thank you for quick reply.
Re-checked soldered correctly, and confirmed continuity to board connector.
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Al, check the electret condenser mic element soldering. Polarity is important.
Raj
toggle quoted message
Show quoted text
At 18-07-18, you wrote: Just finished wiring my bitx40.
Draws ~350ma with PTT, but no change at all when yelling or whistling into mic. (Dummy load present at all times, so don't suspect final blown.)
I see lots of discussion around this issue, but would appreciate advice on how to troubleshoot.
72/3, Al - va3iaw
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Just finished wiring my bitx40.?
Draws ~350ma with PTT, but no change at all when yelling or whistling into mic.? (Dummy load present at all times, so don't suspect final blown.)
I see lots of discussion around this issue, but would appreciate advice on how to troubleshoot.
72/3, Al - va3iaw
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Re: receive works great, but no trans power,
#ubitx-help
That strap could cut Q90-base out of the circuit too, in case that causes RX spurs.
Probably OK to leave the back-to-back diodes in there near Q90-base (to the left of C80)
during transmit, as I doubt we have much more than 0.1vrms there.
Unfortunately, I've got a very long list of stuff to do while the weather is good.
Fiddling with the uBitx isn't on it.
Jerry, KE7ER
toggle quoted message
Show quoted text
On Wed, Jul 18, 2018 at 03:53 AM, Gordon Gibby wrote:
That would make for a very useful experiment! ? If you try it, let us know what you find out!
?
It¡¯s possible that different transistors have different reverse (base-emitter) break down voltages, which would dramatically change the amount of energy deposited on the base-emitter junction by a strong signals.... I just don¡¯t know enough about the devices to say for sure.
?
?
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Re: Need a video on ubitx troubleshooting
Check voltage at R104, should be 0v. Sounds like CW is on!
toggle quoted message
Show quoted text
At 18-07-18, you wrote: I have a ubitx v4 it was workign fine on my 12v 3 amp power brick all fo a sudden whip transmitting the unit shut off and cam back on. Now the reciever is working fine but when I transmit I het a loud carrier with a hum to it and no audio output ... I figure something in the transmit section went bottoms up but looking at it with a usb based microscope I see nothign blown on the board no bubbles on chips and no broken or burnt wires.
any input would be helpfull
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Need a video on ubitx troubleshooting
I have a ubitx v4 it was workign fine on my 12v 3 amp power brick all fo a sudden whip transmitting the unit shut off and cam back on. Now the reciever is working fine but when I transmit I het a loud carrier with a hum to it and no audio output ... I figure something in the transmit section went bottoms up but looking at it with a usb based microscope I see nothign blown on the board no bubbles on chips and no broken or burnt wires.
any input would be helpfull
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Re: receive works great, but no trans power,
#ubitx-help
That would make for a very useful experiment! ? If you try it, let us know what you find out!
It¡¯s possible that different transistors have different reverse (base-emitter) break down voltages, which would dramatically change the amount of energy deposited on the base-emitter junction by a strong signals.... I just don¡¯t know enough about the devices
to say for sure.
On Jul 17, 2018, at 23:30, Jerry Gaffke via Groups.Io < jgaffke@...> wrote:
toggle quoted message
Show quoted text
We have had a couple reports of Q90 frying, but not the mixer.
Perhaps as Gordon notes, these were due to a strong VHF signal.
I believe Gordon has suggested in the past the the failure mode might be?
due to reverse voltage at the BE junction, not forward current.
I have no idea if the back-to-back diodes would significantly contribute to the spurs.
Doubt it would cause trouble where I'm at, as there are no strong local broadcasters.
I should try it, include a strap to remove the diodes if curious about some new spur.
We've got plenty of electrical storms.
Jerry
?
On Tue, Jul 17, 2018 at 01:28 PM, ajparent1/KB1GMX wrote:
It the signals are strong enough to fry Q90 the mixer will soon be gone too.
The BE junction is as robust as the mixer diodes.? so whatever you are seeing
is quite strong and could even be ESD.
For ubitx (V3 or 4) a pair of back to back 1n194/4148 diodes from K3 Pin14 to ground
is the best bet as then its only there for RX and has no impact on TX.
Bitx 20 and 40 the solution is different.
Its easily done on the back of the board.
Allison
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Re: #ubitx #ubitx-help Not able to set up extension switches using CEC firmware
#ubitx
#ubitx-help
Yes, I followed the instructions on the blog and the video. The values that should have been reported by the manager are not the expected results??
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Re: The new uBITX boards are here
Dear Mr Farhan
As about me for several days I was asking for help as I've lost the original soft for scale and control of the Si5351. At last I've? find HEX file by KD8CEC and I am happy that it works!( Used XLoader).
But till this time did not find the original file and besides this I am not the Arduino specialist. A lot of words but no FILE and how to load it!
To my mind the R50 feed back of the Q70 should be raised to 820K to raise collector U from 1.8 to 6 V - not to over load it by strong signals.?
Problems: great carrier in SSB mode TX, more then modulation speech signal! What is it? to use only in reception mode?
The final 12 MHz filter is too wide and do not have 6/60 dB features, + some out of channel signals! But stii very simple and original transceiver not noisy with good sound! Some raising of the price of something 140-150 will not be too much for it. Best regards to you and your team 73! George UR4CRG/RX3ARG
|
K5BCQ click fix 2nd generation installed
#ubitx
I didn't see pics of this in the site, so I thought I'd share mine. Continuity tests all look good. But, man tombstoning those surface mounts was hard! I Now understand why there was a REV 3. :-)  
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Re: I think this will work for the Ubitx...microphone
Kevin
If you search on miklor.com you will find the wiring diagram for
the Baofeng speaker/mic.
You will need to modify the mic to work with the uBITx (but not
the BITX40 or BITX20) because the T/R switch is on high with 5v on
it.
Separate out the switch from the mic internally.
M
On 18/07/18 9:53 AM, Kevin Rea wrote:
Hi guys,
I am just getting ready to build my first Ubitx.
I am going to use a Baofeng Microphone to do it.. so I bought
one and took it apart..
and this is what I came up with after tracing the wires..
I am just using the microhone part of the mike, not the speaker.
I think this will work......????
Kevin Rea
K6REA
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Re: RD16HHF1 power curve flattening...some
Some fake RD16HHF turned out to be IRF510 on my tester. The pin
orientation was IRF and so was capacitance.
They worked fine in my B40 boards.
Raj
At 18-07-18, you wrote:
toggle quoted message
Show quoted text
Farhan jee
? the "c" mark on the right of Logo indicates that devices are
fake.If?? IRF530?? re labelled as indicated that they are fake.
I had a bunch of therm. If some one doen't check under item details for a
comment? ?? "Make: generic / unbranded" They do get fake
ones.
? if we get IRF530 or so re labelled as RD16, Obviously there would be a
short , of course through the internal protection diode.
Regards
MVS Sarma
?
On Wed, Jul 18, 2018 at 11:13 AM, Ashhar Farhan
<farhanbox@...>
wrote:
- Are you sure that the pins are not shorting??
- On Wed, 18 Jul 2018, 10:23 Mvs Sarma,
<mvssarma@...>
wrote:
- I too suspect the devices?? OP bought.?? He could remove
them and test with a DMM for the correctness of pinout.
- ?
- ? I am currently depending for my RD hhf and hvf devices, on an ebay
seller " polida2008" after having suffered fake ones from
another seller.
- ? This seller is now operating with another seller name "?
5hk1584 "
- ? While i have no business deal with this seller(s), I do enjoy
genuine devices for my hobby.?? Hope it helps.
- Regards
- MVS Sarma
- ? vu3zmv
- On Wed, Jul 18, 2018 at 9:02 AM, Kevin Rea
<reakevinscott@...
> wrote:
- On Thu, Mar 8, 2018 at 05:14 PM, "John"
<
passionfruit88@...> wrote:
- Hi John,
- did you mount the new pot in the front or?? back or just leave
it on the breadboard ?
- kevin rea
- lancaster, calif.
- k6rea
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Re: RF power chain mods and improvements..
On Mon, Jun 11, 2018 at 03:54 AM, ajparent1/KB1GMX wrote:
MPSH10 was disappointing.
I just tried these in mine too for pre-driver and drivers. <5w output.... I had some 2n5109 turn up today so will put them in tonight. One under the board one on top. as flat as I can get them... The BFR106 made a big difference in the SMT pre-pre-driver Q90 Will also try them in the 45mhz mixers... 73 Nick VK4PLN
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Re: RD16HHF1 power curve flattening...some
Farhan jee ?the "c" mark on the right of Logo indicates that devices are fake.If? IRF530? re labelled as indicated that they are fake. I had a bunch of therm. If some one doen't check under item details for a comment?? "Make: generic / unbranded" They do get fake ones.
?if we get IRF530 or so re labelled as RD16, Obviously there would be a short , of course through the internal protection diode.
On Wed, Jul 18, 2018 at 11:13 AM, Ashhar Farhan <farhanbox@...> wrote: Are you sure that the pins are not shorting??
I too suspect the devices? OP bought.? He could remove them and test with a DMM for the correctness of pinout. ?
?I am currently depending for my RD hhf and hvf devices, on an ebay seller " polida2008" after having suffered fake ones from another seller. ?This seller is now operating with another seller name "?5hk1584
" ?While i have no business deal with this seller(s), I do enjoy genuine devices for my hobby.? Hope it helps.
|
_Dave_ AD0B
Raj vu2zap
George
Nick VK4PP