Date   
Re: Tracing receive signal for low signal

Dave Space
 



Gave it a try same results 1900uv estimated at tp2 to get to .1p-p

9000uv estimated at tp1 to get .1p-p  (I think I reported my signal generator's input in my message last time and mentioned uv when it was really mv 900mv through a -40b attenuator so estimated at 9000 uv.)

with the wire wrapped through about 5 times (it was about as many as I could fit and it's even thinner magnet wire than they used on T2 itself.)

So perhaps that means its not matching that is the issue?

Re: Tracing receive signal for low signal

Dave Space
 

That's brilliant will have to give that a try, thanks!

Re: Tracing receive signal for low signal

jim
 

Loop several turns of wire thru T2... connect to scope ...Will cause less mismatch than hanging extra cruft on TP-1

Jim


On Tuesday, December 25, 2018, 5:41:06 AM PST, Dave Space <davesspacebar@...> wrote:


Yep I was thinking about the varying the signal generator frequency/scope idea.  I wonder if there is a way without disconnecting T2 - adding some resistance or impedance of some sort to match the input better.

I don't have any of the spectrum analyzers though I do have an rtl sdr but it seems deaf below 100 MHZ or so (not sure why - I had planned to use that for spur analysis later - guess I'll need a different one).

My scope is a hantek 200mhz with 25mhz waveform generator
https://www.amazon.com/Hantek-DSO4202C-Oscilloscope-Arbitrary-Generator/dp/B00ZQUQWII/ref=sr_1_3?ie=UTF8&qid=1545745165&sr=8-3&keywords=hantek+waveform+generator+200mhz

Re: Tracing receive signal for low signal

Evan Hand
 

Glad I can help!

73
Evan
AC9TU

Re: RadioKits.in Case #ubitx

Terence Taylor
 

Thanks, Curt for reminding me about ubitx.com. Found what I needed there.

Re: RadioKits.in Case #ubitx

Curt
 

John, many have done same and found that many toggle switches will fit. Until then okay to jumper it and use the power connection to turn it off with a pull.

Check ubitx.com for case assembly suggestions,  as Sunil maintains this URL. Yes it was an adventure building before I found the rest of the instructions.

Merry Christmas to all builders and users.

Curt

Re: RadioKits.in Case #ubitx

Terence Taylor
 

I have been looking all over, but cannot find a good assembly guide for this case. Can anyone point me in the right direction?

Re: Tracing receive signal for low signal

Dave Space
 

Thanks Evan I think I missed that entire part about the separate config for HF frequencies!  It works great just tried it on my attic 40/20 fan dipole!
You probably just saved me from wasting some money.  I have to learn to read the manual first :)

Re: Tracing receive signal for low signal

Evan Hand
 

I had also tried an rtl-sdr and was able to get it to show a spectrum for my ubitx, however the front end is overloaded fairly easily.  The secret in SDRSharp (SDR#) is to only use the "Direct Sampling (Q branch) in the radio setup.  It is not very sensitive, but I was able to hear my ubitx on it and see a spectrum.   I do not trust it.  Seems it was either overloaded, or could not sense it.  I do not have a good attenuation setup that may be the issue. 

Between your signal generator and attenuater you might be able to calibrate it to work.

I do not have the link that however I started at the following and found the instructions to make it work.

https://www.rtl-sdr.com/rtl-sdr-quick-start-guide/

73
Evan
AC9TU

Re: R60 mic bias

iz oos
 

Thanks Raj for your help! I keep R60 installed as I have some electrets I might want to use. I have to say a compressor like this Vogad really helps. As Barry suggested it fits well with the ubitx. It makes a big change with the ILER QRPs too.


Il 25/dic/2018 15:51, "Raj vu2zap" <rajendrakumargg@...> ha scritto:
Should be OK!

Tomstone R60 and connect direct if you don't want backward compatability
with the original mic provided.

At 25-12-18, you wrote:

Should be the same value of C60 or is it fine also a lower value 0.47uf?

Il 25/dic/2018 15:05, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
Change to 1uF .

At 25-12-18, you wrote:

47uF rated at 35v

Il 25/dic/2018 13:59, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
electrolytic cap (the positive towards the ubitx)
what is the value ?

At 25-12-18, you wrote:

Actually when it becomes stuck if I wait let's say 20seconds then it works again.

Il 25/dic/2018 12:42, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
Check voltages in audio stage and vogad when the audio is gone. That should tell you
where to look!
At 25-12-18, you wrote:

12vdc from the battery, but after a resistor and the 7805 is 5vdc.
Il 25/dic/2018 11:37, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
What is the supply voltage for the VOGAD board ?
At 25-12-18, you wrote:
>Hi all, I have tested a mic compressor based on the VOGAD SL6270C (same schematics of its datasheet), and it works very well on the ILER QRPs. However when connected to the ubitx something weird happens. It works the first time I push to talk, I can talk also 5 minutes, and no problem, BUT when I release the PTT and then press again, it does not transmit anything. I did not remove R60 and put an electrolytic cap (the positive towards the ubitx) in the cable connecting the VOGAD and the ubitx. The VOGAD is always powered on via a battery or the same power supply and is DC isolated from the Ubitx. In fact the interconnecting cable also has an isolating transformer to avoid any possible ground loop. Should I really remove R60? Should I remove the DC power of the VOGAD each time I receive? Or should I simply add some polyester caps in parallel at the mic input?

Re: R60 mic bias

 

Should be OK!

Tomstone R60 and connect direct if you don't want backward compatability
with the original mic provided.


At 25-12-18, you wrote:

Should be the same value of C60 or is it fine also a lower value 0.47uf?

Il 25/dic/2018 15:05, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
Change to 1uF .

At 25-12-18, you wrote:

47uF rated at 35v

Il 25/dic/2018 13:59, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
electrolytic cap (the positive towards the ubitx)
what is the value ?

At 25-12-18, you wrote:

Actually when it becomes stuck if I wait let's say 20seconds then it works again.

Il 25/dic/2018 12:42, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
Check voltages in audio stage and vogad when the audio is gone. That should tell you
where to look!
At 25-12-18, you wrote:

12vdc from the battery, but after a resistor and the 7805 is 5vdc.
Il 25/dic/2018 11:37, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
What is the supply voltage for the VOGAD board ?
At 25-12-18, you wrote:
>Hi all, I have tested a mic compressor based on the VOGAD SL6270C (same schematics of its datasheet), and it works very well on the ILER QRPs. However when connected to the ubitx something weird happens. It works the first time I push to talk, I can talk also 5 minutes, and no problem, BUT when I release the PTT and then press again, it does not transmit anything. I did not remove R60 and put an electrolytic cap (the positive towards the ubitx) in the cable connecting the VOGAD and the ubitx. The VOGAD is always powered on via a battery or the same power supply and is DC isolated from the Ubitx. In fact the interconnecting cable also has an isolating transformer to avoid any possible ground loop. Should I really remove R60? Should I remove the DC power of the VOGAD each time I receive? Or should I simply add some polyester caps in parallel at the mic input?

Re: Setting BFO

Evan Hand
 

You are welcome.

Merry Christmas and Happy New Year!

Evan
AC9TU

Re: R60 mic bias

iz oos
 

Should be the same value of C60 or is it fine also a lower value 0.47uf?


Il 25/dic/2018 15:05, "Raj vu2zap" <rajendrakumargg@...> ha scritto:
Change to 1uF .

At 25-12-18, you wrote:

47uF rated at 35v

Il 25/dic/2018 13:59, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
electrolytic cap (the positive towards the ubitx)
what is the value ?

At 25-12-18, you wrote:

Actually when it becomes stuck if I wait let's say 20seconds then it works again.

Il 25/dic/2018 12:42, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
Check voltages in audio stage and vogad when the audio is gone. That should tell you
where to look!

At 25-12-18, you wrote:

12vdc from the battery, but after a resistor and the 7805 is 5vdc.
Il 25/dic/2018 11:37, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
What is the supply voltage for the VOGAD board ?
At 25-12-18, you wrote:
>Hi all, I have tested a mic compressor based on the VOGAD SL6270C (same schematics of its datasheet), and it works very well on the ILER QRPs. However when connected to the ubitx something weird happens. It works the first time I push to talk, I can talk also 5 minutes, and no problem, BUT when I release the PTT and then press again, it does not transmit anything. I did not remove R60 and put an electrolytic cap (the positive towards the ubitx) in the cable connecting the VOGAD and the ubitx. The VOGAD is always powered on via a battery or the same power supply and is DC isolated from the Ubitx. In fact the interconnecting cable also has an isolating transformer to avoid any possible ground loop. Should I really remove R60? Should I remove the DC power of the VOGAD each time I receive? Or should I simply add some polyester caps in parallel at the mic input?

Re: R60 mic bias

iz oos
 

Solved! The blocking cap was too big! I added in series a 0.47uf electrolytic and the problem vanished. I chose that cap because it is a lower value than C60. I don't fully understand it but it works!!!

Il 25/dic/2018 14:21, "iz oos via Groups.Io" <and2oosiz2=gmail.com@groups.io> ha scritto:
>
> 47uF rated at 35v
>
>
> Il 25/dic/2018 13:59, "Raj vu2zap" <rajendrakumargg@...> ha scritto:
>>>
>>> electrolytic cap (the positive towards the ubitx)
>>
>> what is the value ?
>>
>> At 25-12-18, you wrote:
>>
>>> Actually when it becomes stuck if I wait let's say 20seconds then it works again.
>>>
>>> Il 25/dic/2018 12:42, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
>>> Check voltages in audio stage and vogad when the audio is gone. That should tell you
>>> where to look!
>>>
>>>
>>> At 25-12-18, you wrote:
>>>
>>>> 12vdc from the battery, but after a resistor and the 7805 is 5vdc.
>>>>
>>>> Il 25/dic/2018 11:37, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
>>>> What is the supply voltage for the VOGAD board ?
>>>> At 25-12-18, you wrote:
>>>> >Hi all, I have tested a mic compressor based on the VOGAD SL6270C (same schematics of its datasheet), and it works very well on the ILER QRPs. However when connected to the ubitx something weird happens. It works the first time I push to talk, I can talk also 5 minutes, and no problem, BUT when I release the PTT and then press again, it does not transmit anything. I did not remove R60 and put an electrolytic cap (the positive towards the ubitx) in the cable connecting the VOGAD and the ubitx. The VOGAD is always powered on via a battery or the same power supply and is DC isolated from the Ubitx. In fact the interconnecting cable also has an isolating transformer to avoid any possible ground loop. Should I really remove R60? Should I remove the DC power of the VOGAD each time I receive? Or should I simply add some polyester caps in parallel at the mic input?
>

Re: R60 mic bias

 

Change to 1uF .


At 25-12-18, you wrote:

47uF rated at 35v

Il 25/dic/2018 13:59, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
electrolytic cap (the positive towards the ubitx)
what is the value ?

At 25-12-18, you wrote:

Actually when it becomes stuck if I wait let's say 20seconds then it works again.

Il 25/dic/2018 12:42, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
Check voltages in audio stage and vogad when the audio is gone. That should tell you
where to look!

At 25-12-18, you wrote:

12vdc from the battery, but after a resistor and the 7805 is 5vdc.
Il 25/dic/2018 11:37, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
What is the supply voltage for the VOGAD board ?
At 25-12-18, you wrote:
>Hi all, I have tested a mic compressor based on the VOGAD SL6270C (same schematics of its datasheet), and it works very well on the ILER QRPs. However when connected to the ubitx something weird happens. It works the first time I push to talk, I can talk also 5 minutes, and no problem, BUT when I release the PTT and then press again, it does not transmit anything. I did not remove R60 and put an electrolytic cap (the positive towards the ubitx) in the cable connecting the VOGAD and the ubitx. The VOGAD is always powered on via a battery or the same power supply and is DC isolated from the Ubitx. In fact the interconnecting cable also has an isolating transformer to avoid any possible ground loop. Should I really remove R60? Should I remove the DC power of the VOGAD each time I receive? Or should I simply add some polyester caps in parallel at the mic input?

BFO frequencies that work ubitx

_Dave_ K0MBT
 

I see a lot of posts where Amateurs are complaining about distorted sound. I have been through that with everyone of our ubitx radios. Once the frequency display has been calibrated I have seen bfos over 12,000,000 hz. Many times I can hear points that seem to work at 11,80x,xxx but not clear and many times there is a tone along with the audio.

My oldest unit build date, about feb 2018 now has a bfo of 11,996,635.
The second unit was built in mid Feb 2018 has a raduino clone card in it and has a bfo of 11,996,455. The third unit, the newest A more recent v4 build has a bfo setting of 11,996,515hz.

Before you calibrate the bfo, zero beat your radio on to a commercial AM station. I have tried wwv and found the tones that they play makes using it more confusing than anything else. I figure that a commercial station has way better frequency measuring capability than I have. The v4 unit has much less audio output than the older ones.

I believe that the ubitx board has been tested by the factory before it has shipped.

Re: Tracing receive signal for low signal

Dave Space
 

Yep I was thinking about the varying the signal generator frequency/scope idea.  I wonder if there is a way without disconnecting T2 - adding some resistance or impedance of some sort to match the input better.

I don't have any of the spectrum analyzers though I do have an rtl sdr but it seems deaf below 100 MHZ or so (not sure why - I had planned to use that for spur analysis later - guess I'll need a different one).

My scope is a hantek 200mhz with 25mhz waveform generator
https://www.amazon.com/Hantek-DSO4202C-Oscilloscope-Arbitrary-Generator/dp/B00ZQUQWII/ref=sr_1_3?ie=UTF8&qid=1545745165&sr=8-3&keywords=hantek+waveform+generator+200mhz

Re: R60 mic bias

iz oos
 

47uF rated at 35v


Il 25/dic/2018 13:59, "Raj vu2zap" <rajendrakumargg@...> ha scritto:
electrolytic cap (the positive towards the ubitx)
what is the value ?

At 25-12-18, you wrote:

Actually when it becomes stuck if I wait let's say 20seconds then it works again.

Il 25/dic/2018 12:42, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
Check voltages in audio stage and vogad when the audio is gone. That should tell you
where to look!


At 25-12-18, you wrote:

12vdc from the battery, but after a resistor and the 7805 is 5vdc.

Il 25/dic/2018 11:37, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
What is the supply voltage for the VOGAD board ?
At 25-12-18, you wrote:
>Hi all, I have tested a mic compressor based on the VOGAD SL6270C (same schematics of its datasheet), and it works very well on the ILER QRPs. However when connected to the ubitx something weird happens. It works the first time I push to talk, I can talk also 5 minutes, and no problem, BUT when I release the PTT and then press again, it does not transmit anything. I did not remove R60 and put an electrolytic cap (the positive towards the ubitx) in the cable connecting the VOGAD and the ubitx. The VOGAD is always powered on via a battery or the same power supply and is DC isolated from the Ubitx. In fact the interconnecting cable also has an isolating transformer to avoid any possible ground loop. Should I really remove R60? Should I remove the DC power of the VOGAD each time I receive? Or should I simply add some polyester caps in parallel at the mic input?

Re: R60 mic bias

 

electrolytic cap (the positive towards the ubitx)
what is the value ?

At 25-12-18, you wrote:

Actually when it becomes stuck if I wait let's say 20seconds then it works again.

Il 25/dic/2018 12:42, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
Check voltages in audio stage and vogad when the audio is gone. That should tell you
where to look!


At 25-12-18, you wrote:

12vdc from the battery, but after a resistor and the 7805 is 5vdc.

Il 25/dic/2018 11:37, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
What is the supply voltage for the VOGAD board ?
At 25-12-18, you wrote:
>Hi all, I have tested a mic compressor based on the VOGAD SL6270C (same schematics of its datasheet), and it works very well on the ILER QRPs. However when connected to the ubitx something weird happens. It works the first time I push to talk, I can talk also 5 minutes, and no problem, BUT when I release the PTT and then press again, it does not transmit anything. I did not remove R60 and put an electrolytic cap (the positive towards the ubitx) in the cable connecting the VOGAD and the ubitx. The VOGAD is always powered on via a battery or the same power supply and is DC isolated from the Ubitx. In fact the interconnecting cable also has an isolating transformer to avoid any possible ground loop. Should I really remove R60? Should I remove the DC power of the VOGAD each time I receive? Or should I simply add some polyester caps in parallel at the mic input?

Re: R60 mic bias

iz oos
 

Actually when it becomes stuck if I wait let's say 20seconds then it works again.


Il 25/dic/2018 12:42, "Raj vu2zap" <rajendrakumargg@...> ha scritto:
Check voltages in audio stage and vogad when the audio is gone. That should tell you
where to look!


At 25-12-18, you wrote:

12vdc from the battery, but after a resistor and the 7805 is 5vdc.

Il 25/dic/2018 11:37, "Raj vu2zap" < rajendrakumargg@...> ha scritto:
What is the supply voltage for the VOGAD board ?

At 25-12-18, you wrote:

>Hi all, I have tested a mic compressor based on the VOGAD SL6270C (same schematics of its datasheet), and it works very well on the ILER QRPs. However when connected to the ubitx something weird happens. It works the first time I push to talk, I can talk also 5 minutes, and no problem, BUT when I release the PTT and then press again, it does not transmit anything. I did not remove R60 and put an electrolytic cap (the positive towards the ubitx) in the cable connecting the VOGAD and the ubitx. The VOGAD is always powered on via a battery or the same power supply and is DC isolated from the Ubitx. In fact the interconnecting cable also has an isolating transformer to avoid any possible ground loop. Should I really remove R60? Should I remove the DC power of the VOGAD each time I receive? Or should I simply add some polyester caps in parallel at the mic input?