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BITX40 Transistor Voltage Measurements


 

Hi

I measured all the transistor voltages for both receive and transmit and entered all that data into a document.

I believe my BITX40 is operating normally.?

Please let me know of any errors.

I will upload this into the FILE section when we are allowed.

Enjoy,

Randy, K7AGE



 

Thanks Randy!


G4NQX
 

Hi Randy,

Thanks for that.? I will include them in the Tips doc.? I'm hoping at least two others will do the same so we can have a typical set of voltages.
--
Rob G4NQX


Jim Schliestett
 

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Wow Randy, way to go, thanks.

?

From: [email protected] [mailto:[email protected]] On Behalf Of Randy Hall
Sent: Monday, February 06, 2017 2:44 PM
To: [email protected]
Subject: [BITX20] BITX40 Transistor Voltage Measurements

?

Hi

I measured all the transistor voltages for both receive and transmit and entered all that data into a document.

I believe my BITX40 is operating normally.?

Please let me know of any errors.

I will upload this into the FILE section when we are allowed.

Enjoy,

Randy, K7AGE

?


 

Rob,

They can use the spreadsheet and replace my data with their data.

Thanks for including the data.

Randy


On Mon, Feb 6, 2017 at 1:12 PM, G4NQX <tasmod@...> wrote:

Hi Randy,

Thanks for that.? I will include them in the Tips doc.? I'm hoping at least two others will do the same so we can have a typical set of voltages.
--
Rob G4NQX



 

That's one of the most helpful things I've seen here.

I'll be comparing mine with this stock data.

Keeping in mind my DMM is like a hand grenade.

Does yours have the expected current and wattage measurements?


 

John

Thanks, my DMM does do current measurements.?

I use either my LP-100A or Diamond SX-600 for RF power measurements.

Randy


On Mon, Feb 6, 2017 at 3:20 PM, John Smith via Groups.Io <johnlinux77@...> wrote:

That's one of the most helpful things I've seen here.

I'll be comparing mine with this stock data.

Keeping in mind my DMM is like a hand grenade.

Does yours have the expected current and wattage measurements?



 

I can confirm Randy's results, except for Gate of Q15. Mine is only 4.3V, but that is maybe due to my adjusting the idle current to exactly 0.1A.

All other measurements are within 0.1V error, that can be a meter issue or small variations due to component tolerances.

The method and conditions of measurements are the same the same (GND at power jack, power at PWR1 (not PA PWR, 13.7V in receive, 13.6V in transmit)
--
Ion

VA3NOI


G4NQX
 

When I originally asked for this I was hoping for a flood of participants, seems they are all shy :-)

OK that's two then agreeing voltages.? I would be happy if we could get one more agreeing then I will put it in Tips n Mods.

Thanks guys.
--
Rob G4NQX


Jack Purdum
 

Right now, for me it's not a question of being shy. It's a question of body parts lying all over the bench right now. All I need is some time to get the body parts together and a lightning storm so I can yell: "IT'S ALIVE!".

Jack, W8TEE



From: G4NQX <tasmod@...>
To: [email protected]
Sent: Monday, February 6, 2017 7:50 PM
Subject: Re: [BITX20] BITX40 Transistor Voltage Measurements

When I originally asked for this I was hoping for a flood of participants, seems they are all shy :-)
OK that's two then agreeing voltages.? I would be happy if we could get one more agreeing then I will put it in Tips n Mods.
Thanks guys.
--
Rob G4NQX



 

Ion

I'm amazed that our measurements were so close.

Thanks for taking the time to measure.

Randy, K7AGE


On Mon, Feb 6, 2017 at 4:39 PM, Ion Petroianu <ion.petroianu@...> wrote:

I can confirm Randy's results, except for Gate of Q15. Mine is only 4.3V, but that is maybe due to my adjusting the idle current to exactly 0.1A.

All other measurements are within 0.1V error, that can be a meter issue or small variations due to component tolerances.

The method and conditions of measurements are the same the same (GND at power jack, power at PWR1 (not PA PWR, 13.7V in receive, 13.6V in transmit)
--
Ion

VA3NOI



 

Jack

A couple of books arrived today. Lots to dig through.

Randy, K7AGE


On Mon, Feb 6, 2017 at 5:04 PM, Jack Purdum via Groups.Io <econjack@...> wrote:
Right now, for me it's not a question of being shy. It's a question of body parts lying all over the bench right now. All I need is some time to get the body parts together and a lightning storm so I can yell: "IT'S ALIVE!".

Jack, W8TEE



From: G4NQX <tasmod@...>
To: [email protected]
Sent: Monday, February 6, 2017 7:50 PM
Subject: Re: [BITX20] BITX40 Transistor Voltage Measurements

When I originally asked for this I was hoping for a flood of participants, seems they are all shy :-)
OK that's two then agreeing voltages.? I would be happy if we could get one more agreeing then I will put it in Tips n Mods.
Thanks guys.
--
Rob G4NQX




M Garza
 

I am not shy either, I just do not have my radio yet.? It should be here, any day now....

Marco - KG5PRT?

On Feb 6, 2017 7:05 PM, "Jack Purdum via Groups.Io" <econjack=[email protected]> wrote:
Right now, for me it's not a question of being shy. It's a question of body parts lying all over the bench right now. All I need is some time to get the body parts together and a lightning storm so I can yell: "IT'S ALIVE!".

Jack, W8TEE



From: G4NQX <tasmod@...>
To: [email protected]
Sent: Monday, February 6, 2017 7:50 PM
Subject: Re: [BITX20] BITX40 Transistor Voltage Measurements

When I originally asked for this I was hoping for a flood of participants, seems they are all shy :-)
OK that's two then agreeing voltages.? I would be happy if we could get one more agreeing then I will put it in Tips n Mods.
Thanks guys.
--
Rob G4NQX




 

Vishay spec's the Vgs(th) to be anywhere between 2 and 4 volts. ?So your gate bias for a 100ma drain current could likewise be different by as much as 2 volts and still be in spec. ?

?If you swap out a blown IRF510 with a new one and just power up, it could immediately blow the new one. So important to set bias to minimum when swapping it out, and go through the bias adjustment procedure at power up.

Jerry, KE7ER

On Mon, Feb 6, 2017 at 04:39 pm, Ion Petroianu wrote:

I can confirm Randy's results, except for Gate of Q15. Mine is only 4.3V, but that is maybe due to my adjusting the idle current to exactly 0.1A.

?


 

Rob,

Here are my Voltage Measurements before I replaced the IF510 transistor.

I'll do it over and send the final measurements..

Chris N1CFB


 

Hi Randy,


Thanks for your info. My bitx40 had no power in tx, I compared the voltage on all transistors with your measurements and this way found q13 defective.

replacing it with a new one was easier than i thought, and my bitx now has 5w rf output in cw !


73,


Lex.


 

Lex

Glad to hear that it helped.

Randy

On Sat, Apr 29, 2017 at 11:07 AM, <lexhw2@...> wrote:

Hi Randy,


Thanks for your info. My bitx40 had no power in tx, I compared the voltage on all transistors with your measurements and this way found q13 defective.

replacing it with a new one was easier than i thought, and my bitx now has 5w rf output in cw !


73,


Lex.