Date   

Re: Ubitx V4 - What is RV4 supposed to do?

 

RV4 is the VOLUME control and in the diagram clip what you have highlighted is RV1 the power lever set preset.
RV4 is not shown in your V4 diagram.

Raj


At 16/11/2021, you wrote:
I recently received a uBitx V4 kit that was 99% complete.  It didn't take much to get it working, but now to get it working well...  If I can get it operating reasonably well, I may pass it to my brother with the intent of getting him started in amateur radio.  I don't see any specification for what the potentiometer RV4 does, or the method of proper adjustment.  If anyone knows, can they point me in the right direction?   TP2 is on the base of Q90 and TP3 is on the wiper of the pot.  Is there a document that describes any/all of the circuits and adjustments?TIARich - W6BOT[]  


Re: Ubitx V4 - What is RV4 supposed to do?

Skip Davis
 

Rich that is the drive level to amplifier stages it can be adjusted up or down to vary the output. I adjusted it using the 40meter band and set it to get peak out and then backed it off a touch. I think I ended up with around ten watts or maybe a bit more. I later did some mods and set it for ten watts on 40.

73,
Skip Davis, NC9O

On Nov 15, 2021, at 23:26, RichW6BOT <rich.allen.gordon@...> wrote:

I recently received a uBitx V4 kit that was 99% complete.  It didn't take much to get it working, but now to get it working well...  

If I can get it operating reasonably well, I may pass it to my brother with the intent of getting him started in amateur radio.  I don't see any specification for what the potentiometer RV4 does, or the method of proper adjustment.  If anyone knows, can they point me in the right direction?   TP2 is on the base of Q90 and TP3 is on the wiper of the pot.  Is there a document that describes any/all of the circuits and adjustments?

TIA

Rich - W6BOT

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Ubitx V4 - What is RV4 supposed to do?

RichW6BOT
 

I recently received a uBitx V4 kit that was 99% complete.  It didn't take much to get it working, but now to get it working well...  

If I can get it operating reasonably well, I may pass it to my brother with the intent of getting him started in amateur radio.  I don't see any specification for what the potentiometer RV4 does, or the method of proper adjustment.  If anyone knows, can they point me in the right direction?   TP2 is on the base of Q90 and TP3 is on the wiper of the pot.  Is there a document that describes any/all of the circuits and adjustments?

TIA

Rich - W6BOT


 


Re: Straight key problem V6 replay

Bill Cromwell
 

Hi,

Cw in the stock uBitX was not very good. Farhan has testified that he is NOT a CW op. In my case I installed the CEC software but I don't think that is the root of your problem. I think my previous post about the plug is where you get resolution.

73,

Bill KU8H

bark less - wag more

On 11/15/21 7:58 PM, David Wilcox K8WPE via groups.io wrote:
But that doesn’t explain why a set of paddles works using the Dah key when the setup is set for “hand key”.  It does work, just uses different connections so processor speed must be satisfactory. Just the straight key is hooked up wrong to the processor. At least that is what I am thinking…… and I am not really up to speed on how the uBitx works for CW.  Any more thoughts?  I really want this to work stock before I screw it up with upgrades or mods.

Dave K8WPE

David J. Wilcox’s iPad

On Nov 15, 2021, at 7:36 PM, Paul Jensen via groups.io <wkend_traveler@...> wrote:

On Mon, Nov 15, 2021 at 03:32 PM, David Wilcox K8WPE wrote:

Any ideas as to what the cause might be?

From memory, this is a software issue combined with a slow processor
(Nano).  The software reads an a/d converter that looks at the key pin.  During the voltage transition (key press), it can read an intermediate voltage.

The only solution is a faster processor.  I went with the teensy processor solution (by w0eb <http://www.w0eb.com/>).  This works great.  I can hook up a keyboard, use a keyer and a straight key.  Never messes up.  The user interface is well done and quite pleasing to use.

I have a icom 7300 sitting next to the ubitx.  I tune around the bands with the ubitx.  It is more fun to use and is pleasant to listen to.  Perfect for listening to code practice.  If I hear something good, I will use the icom to transmit.


Re: V6.1 Blown output transistors and pcb trace #v6 #ubitxv6-help

Stan K3PW
 

Ok, I see your idea, Sigi. Very good.  When I burnt the trace I was using an ordinary 20a 13.8v switching supply.  Now I have the radio on my workbench and I’m using an adjustable current limiting bench supply.  So, I can set the maximum current it will supply while I’m testing.


Re: Straight key problem V6 replay

Bill Cromwell
 

Hi Dave,

I could be barking up the wrong tree or even be in wrong forest but I recall something about requiring a 'stereo' plug on the cable from the straight key and it isn't wired like our legacy straight keys. I would connect the contacts used in your paddle and connected to the dah and wire up a cable with a stereo connector for your straight key. I have succeeded with a straight key and my V3 and it has the plug wired with a 'stereo' connector. You have nothing to lose giving that a try:)

73,

Bill KU8H

bark less - wag more

On 11/15/21 6:31 PM, David Wilcox K8WPE via groups.io wrote:
After looking over my new Version 6 uBitx and enjoying it I have discovered an issue regarding using a straight key. As I had mentioned in a previous email to the group when in “hand key” mode and using a straight key when I press down using the key (actually trying three different keys) it makes a squeak and occasionally will hold the side tone irrationally but I can’t use it to send. It sounds like dirty contacts but cleaning them makes no difference. BUT if I insert a set of paddles I can use the dah paddle all day sending like a straight key (still in the “hand key” mode).

I pulled out the board and closely examined the key jack. All looks great and the soldering looks excellent. I reheated the solder contacts anyway but no change. I am probably going to wire up a straight key using the same plug and contacts as a dah paddle and see how it goes.

I checked the contacts in the key jack under high power magnification and with an ohm meter and all seems according to the schematic as far as I can see. Some have advised to use the N8ME firmware but if there is an error or short somewhere I doubt that will fix the issue.

Any ideas as to what the cause might be? I can live with it but would like to figure this out.

Dave K8WPE

David J. Wilcox’s iPad




Re: Straight key problem V6 replay

David Wilcox K8WPE
 

But that doesn’t explain why a set of paddles works using the Dah key when the setup is set for “hand key”.  It does work, just uses different connections so processor speed must be satisfactory. Just the straight key is hooked up wrong to the processor. At least that is what I am thinking…… and I am not really up to speed on how the uBitx works for CW.  Any more thoughts?  I really want this to work stock before I screw it up with upgrades or mods.

Dave K8WPE

David J. Wilcox’s iPad

On Nov 15, 2021, at 7:36 PM, Paul Jensen via groups.io <wkend_traveler@...> wrote:

On Mon, Nov 15, 2021 at 03:32 PM, David Wilcox K8WPE wrote:
Any ideas as to what the cause might be?
From memory, this is a software issue combined with a slow processor (Nano).  The software reads an a/d converter that looks at the key pin.  During the voltage transition (key press), it can read an intermediate voltage.

The only solution is a faster processor.  I went with the teensy processor solution (by w0eb).  This works great.  I can hook up a keyboard, use a keyer and a straight key.  Never messes up.  The user interface is well done and quite pleasing to use. 

I have a icom 7300 sitting next to the ubitx.  I tune around the bands with the ubitx.  It is more fun to use and is pleasant to listen to.  Perfect for listening to code practice.  If I hear something good, I will use the icom to transmit.


Re: V6.1 Blown output transistors and pcb trace #v6 #ubitxv6-help

Siegfried Jackstien
 

wire the pa separate ... use for first smoke (bench) test a current regulated bench psu

(either for onlys pa section or just for the complete rig)

if current is too high (blown final or a dead short somewhere) you will not burn up the traces

dg9bfc sigi

Am 16.11.2021 um 00:09 schrieb Stan Mason:

Thanks for the suggestions, Evan.  It’s good to know about the file from VU2ZAP (great call!) and I believe I’m in good shape with the repaired trace.  We’ll see…

Thanks for comment Sigi.  I’m sure the commenter who mentioned higher pa voltage appreciates it.  I’m interested in that sort of mod - eventually - but now it’s just getting it transmit without blowing the finals. :-)

73 Stan K3PW


Re: KD8CEC firmware v1.2 with factory display

Evan Hand
 

hi Howard,

The answer is no, there is not enough room in the KD8CEC firmware to allow for the screen painting that the stock display requires.  The KD8CEC firmware works with one of the text displays or one of the Nextion displays.  The text display is a simple interface, and the Nextion graphics display has its own processor for heavy graphics manipulation.

There is a 2.8" Nextion display that fits in the stock case with only a little bit of filing on the display hole.  there is also a Teensy Raduino board available from others that can drive the display and has reserve processing capabilities that you could add more features through software.

At a minimum, I would look at either Reed N's firmware or N8ME software that can be run with the stock hardware.  They correct some issues with frequency scrolling and CW operation.  They are free and can be found in the files section of this reflector for the N8ME or GitHub for Reed N's

73
Evan
AC9TU


Re: Straight key problem V6 replay

Paul Jensen
 

On Mon, Nov 15, 2021 at 03:32 PM, David Wilcox K8WPE wrote:
Any ideas as to what the cause might be?
From memory, this is a software issue combined with a slow processor (Nano).  The software reads an a/d converter that looks at the key pin.  During the voltage transition (key press), it can read an intermediate voltage.

The only solution is a faster processor.  I went with the teensy processor solution (by w0eb).  This works great.  I can hook up a keyboard, use a keyer and a straight key.  Never messes up.  The user interface is well done and quite pleasing to use. 

I have a icom 7300 sitting next to the ubitx.  I tune around the bands with the ubitx.  It is more fun to use and is pleasant to listen to.  Perfect for listening to code practice.  If I hear something good, I will use the icom to transmit.


Straight key problem V6 replay

David Wilcox K8WPE
 

After looking over my new Version 6 uBitx and enjoying it I have discovered an issue regarding using a straight key. As I had mentioned in a previous email to the group when in “hand key” mode and using a straight key when I press down using the key (actually trying three different keys) it makes a squeak and occasionally will hold the side tone irrationally but I can’t use it to send. It sounds like dirty contacts but cleaning them makes no difference. BUT if I insert a set of paddles I can use the dah paddle all day sending like a straight key (still in the “hand key” mode).

I pulled out the board and closely examined the key jack. All looks great and the soldering looks excellent. I reheated the solder contacts anyway but no change. I am probably going to wire up a straight key using the same plug and contacts as a dah paddle and see how it goes.

I checked the contacts in the key jack under high power magnification and with an ohm meter and all seems according to the schematic as far as I can see. Some have advised to use the N8ME firmware but if there is an error or short somewhere I doubt that will fix the issue.

Any ideas as to what the cause might be? I can live with it but would like to figure this out.

Dave K8WPE

David J. Wilcox’s iPad


Re: V6.1 Blown output transistors and pcb trace #v6 #ubitxv6-help

Stan K3PW
 

Thanks for the suggestions, Evan.  It’s good to know about the file from VU2ZAP (great call!) and I believe I’m in good shape with the repaired trace.  We’ll see…

Thanks for comment Sigi.  I’m sure the commenter who mentioned higher pa voltage appreciates it.  I’m interested in that sort of mod - eventually - but now it’s just getting it transmit without blowing the finals. :-)

73 Stan K3PW


KD8CEC firmware v1.2 with factory display

K4LXY
 

Can the KD8CEC v1.2 firmware be used with the standard factory display in v6?

I guess I can probably download the sketch -I should be able to tell from that - but I'd appreciate any information.

I used his firmware long ago with v3 and liked it.

Thanks

73 Howard K4LXY


Re: V6.1 Blown output transistors and pcb trace #v6 #ubitxv6-help

Siegfried Jackstien
 

if you can wire the pa with higher voltage i bet only the 12v rail is over power switch

no bias (12v off) no current on 18v (or whatever) rail (voltage yes ... current no)

dg9bfc sigi

Am 15.11.2021 um 19:53 schrieb Stan Mason:

Yes, I believe it does, Barry.


Re: V6.1 Blown output transistors and pcb trace #v6 #ubitxv6-help

Evan Hand
 

Stan,

Also, I would be sure that you have repaired the short that burned out the trace before you try transmitting again.


Re: V6.1 Blown output transistors and pcb trace #v6 #ubitxv6-help

Evan Hand
 

Stan,

Do a search in the files section of this list server for vu2zap.  Raj recorded measurements of the transistors, not the test points.  It is for a version 4 uBitx, but other than the first IF amps, the RF circuits are pretty much the same.

73
Evan
AC9TU


Re: V6.1 Blown output transistors and pcb trace #v6 #ubitxv6-help

Stan K3PW
 

Thanks, Dave.  

The process you describe is what I found on the HF Signals website.  I guess setting up the PA Bias is my next step.

I’m still very interested if anyone knows of a listing of what voltages and/or waveforms are normal for the different test points on the V6 board.

Stan K3PW


Re: V6.1 Blown output transistors and pcb trace #v6 #ubitxv6-help

AC9QC
 

It's likely not the case but I'd hook a basic DVM up to the load you used and ensure there's not a short or something there. Highly unlikely but why take chances?


Re: V6.1 Blown output transistors and pcb trace #v6 #ubitxv6-help

barry halterman
 

Thanks for that info. I personally, would like to see the power to the finals split like in the old days when you could feed the radio with 12 volts and the IRF510 with a higher voltage.
I couldn't remember if final power went through the on-off switch in the V6. Been away from it for awhile.
Barry

On Mon, Nov 15, 2021, 2:11 PM _Dave_ AD0B <davesters@...> wrote:
My first thought is that it might be that the bias on the output was set too high. When I have set the bias on mine have found it very sensitive. Although since the power on 20 and 30 were fairly nominal that may not be the issue but you will have set the bias anyway. If I recall the pots had to be turned full on to lower the bias then you back them off. It has been several years since I have had that to do.

So it might be thinking that perhaps that is a short affecting the 40m circuit past the transistors. Perhaps a shorted cap in  the output filter.

I have found that I get better audio on the receiver with less voltage so I added in a diode in series with the receiver PS. But have run the finals on a separate PS at 20v courtesy of an ex-laptop power supply. I don't believe that the voltage you used was a factor at all. 
--
73
Dave
ADOB
Raduino bracket and Ham_Made_Keys


Re: V6.1 Blown output transistors and pcb trace #v6 #ubitxv6-help

_Dave_ AD0B
 

My first thought is that it might be that the bias on the output was set too high. When I have set the bias on mine have found it very sensitive. Although since the power on 20 and 30 were fairly nominal that may not be the issue but you will have set the bias anyway. If I recall the pots had to be turned full on to lower the bias then you back them off. It has been several years since I have had that to do.

So it might be thinking that perhaps that is a short affecting the 40m circuit past the transistors. Perhaps a shorted cap in  the output filter.

I have found that I get better audio on the receiver with less voltage so I added in a diode in series with the receiver PS. But have run the finals on a separate PS at 20v courtesy of an ex-laptop power supply. I don't believe that the voltage you used was a factor at all. 
--
73
Dave
ADOB
Raduino bracket and Ham_Made_Keys

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