Re: Heatsink for the 49'r?
Someone once told me:
? ? ?All electronic devices run on white smoke. Once the smoke gets out, the device dies.
Seems to be true...
Jack, W8TEE
From: "Aaron Heverin aaronhev@... [SoftwareControlledHamRadio]"
To: SoftwareControlledHamRadio@...
Sent: Tuesday, April 19, 2016 9:44 PM
Subject: Re: [SoftwareControlledHamRadio] Heatsink for the 49'r?
?
Hi Steve. I can tell you first hand that the D882 MUST have a heatsink on it. I actually blew mine up the other day... not necessarily because it was running hot, but because I made an error in adjusting the peak-to-peak voltage from R1 on the DDS VFO board. Thanks to Dennis' input on the subject, I found that the voltage on my DDS was somewhere in the neighborhood of 11 volts and NOT 4 volts! Needless to say, the 49-er operated for a time... then the D882 just popped and the smoke went flying. A TO-126 case is plastic. Even with the 49-er operating at the correct voltage, the D882 is going to be very warm (almost hot) - which mine was before I fiddled with the peak-to-peak voltage adjustment and blew it up.?
You'll have to come up with some clever mounting techniques in order to place the heatsink on the transistor then mount it in its correct spot on the 49-er. A possibility is to mount it with the leads bent at 90 degrees to the board. Of course, that means you've got the transistor/heatsink sticking out the side of the 49-er. If you search for "TO-126 Heatsink", there are several options that come up that may fit in the tight spot on the 49-er board.
I've ordered 20 replacement D882s from Tayda Electronics. Once they come in, I'll be able to play with the heatsinks I have on hand to see what works as far as mounting the combo on the 49-er.
Aaron - N2HTL
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Re: Heatsink for the 49'r?
All:
It wouldn't hurt to put one on, especially if you're running over 12V on the board. I've not tested it, but i read somewhere that the PA transistor get very hot above 12V.
Jack, W8TEE
From: "ns3l@... [SoftwareControlledHamRadio]"
To: SoftwareControlledHamRadio@...
Sent: Tuesday, April 19, 2016 9:05 PM
Subject: [SoftwareControlledHamRadio] Heatsink for the 49'r?
?
I've seen some images of Forty9'rs with small heat sinks.. What is the consensus on this.. Is there enough heat generated to warrant adding one.. particularly in smaller enclosures, or should good ventilation be enough ??
What have users found that works as a good bolt on one?
Steve NS3L
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Re: Capacitor for the LC Circuit is a 56pF
You can order the parts for the 49-er modifications - along with pretty much anything else you'd need - from either Debco Electronics (), or from Tayda Electronics (). I've actually ordered from both on Jack's recommendation, although Debco is right in Ohio and the shipping was blazing fast. The owners are both hams and very nice people to deal with. Prices at both places are pennies for these small components. Keep in mind that although both stores may have the same values in caps, inductors, and other parts... one may have a selection of products the other doesn't so plan your shopping list accordingly. :-)
Aaron - N2HTL
?
Steve:
??? Forty-9er parts are on the way, should be there Friday or Saturday.? A couple of 56pf and 22 uH.? Also some additional stuff you might need.
Frank Moskal
?
-----Original Message-----
From: "ns3l@... [SoftwareControlledHamRadio]"
Sent: Apr 19, 2016 8:40 AM
To: SoftwareControlledHamRadio@...
Subject: Re: [SoftwareControlledHamRadio] Re: Capacitor for the LC Circuit is a 56pF
?
Thanks Frank My address is good on my qrz page..
Thanks to the others.. I still need the 56pf capacitor so if someone has that I'd like to have one..
My local RS didn't have the cap, but I did get the 5.1V zener.
Steve
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Re: Heatsink for the 49'r?
Hi Steve. I can tell you first hand that the D882 MUST have a heatsink on it. I actually blew mine up the other day... not necessarily because it was running hot, but because I made an error in adjusting the peak-to-peak voltage from R1 on the DDS VFO board. Thanks to Dennis' input on the subject, I found that the voltage on my DDS was somewhere in the neighborhood of 11 volts and NOT 4 volts! Needless to say, the 49-er operated for a time... then the D882 just popped and the smoke went flying. A TO-126 case is plastic. Even with the 49-er operating at the correct voltage, the D882 is going to be very warm (almost hot) - which mine was before I fiddled with the peak-to-peak voltage adjustment and blew it up.?
You'll have to come up with some clever mounting techniques in order to place the heatsink on the transistor then mount it in its correct spot on the 49-er. A possibility is to mount it with the leads bent at 90 degrees to the board. Of course, that means you've got the transistor/heatsink sticking out the side of the 49-er. If you search for "TO-126 Heatsink", there are several options that come up that may fit in the tight spot on the 49-er board.
I've ordered 20 replacement D882s from Tayda Electronics. Once they come in, I'll be able to play with the heatsinks I have on hand to see what works as far as mounting the combo on the 49-er.
Aaron - N2HTL
?
I've seen some images of Forty9'rs with small heat sinks.. What is the consensus on this.. Is there enough heat generated to warrant adding one.. particularly in smaller enclosures, or should good ventilation be enough ??
What have users found that works as a good bolt on one?
Steve NS3L
|
I've seen some images of Forty9'rs with small heat sinks.. What is the consensus on this.. Is there enough heat generated to warrant adding one.. particularly in smaller enclosures, or should good ventilation be enough ??
What have users found that works as a good bolt on one?
Steve NS3L
|
Re: Capacitor for the LC Circuit is a 56pF
|
Re: Capacitor for the LC Circuit is a 56pF
Steve:
??? Forty-9er parts are on the way, should be there Friday or Saturday.? A couple of 56pf and 22 uH.? Also some additional stuff you might need.
Frank Moskal
?
-----Original Message-----
From: "ns3l@... [SoftwareControlledHamRadio]"
Sent: Apr 19, 2016 8:40 AM
To: SoftwareControlledHamRadio@...
Subject: Re: [SoftwareControlledHamRadio] Re: Capacitor for the LC Circuit is a 56pF
?
Thanks Frank My address is good on my qrz page..
Thanks to the others.. I still need the 56pf capacitor so if someone has that I'd like to have one..
My local RS didn't have the cap, but I did get the 5.1V zener.
Steve
|
Re: Capacitor for the LC Circuit is a 56pF
Thanks Frank My address is good on my qrz page..
Thanks to the others.. I still need the 56pf capacitor so if someone has that I'd like to have one..
My local RS didn't have the cap, but I did get the 5.1V zener.
Steve
|
Re: Capacitor for the LC Circuit is a 56pF
Steve:
???? If that is a 22uH inductor then? Mouser part no. 70-IM2-22.? Give me your address and I'll send you a couple.
Frank Moskal
kayandfrank@...
-----Original Message-----
From: "ns3l@... [SoftwareControlledHamRadio]"
Sent: Apr 19, 2016 4:13 AM
To: SoftwareControlledHamRadio@...
Subject: [SoftwareControlledHamRadio] Re: Capacitor for the LC Circuit is a 56pF
?
Where can I purchase the 22uf inductor.. I doub't my local radio shack has these..I know I can most likely get the 56pf cap from RSbut right now I have the 49'r kit underway and need this one part..
Steve NS3L
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Re: Capacitor for the LC Circuit is a 56pF
My post on April 10 gives the supplier's URL:
I find them to be a good source for parts like this.
Jack, W8TEE
From: "ns3l@... [SoftwareControlledHamRadio]" To: SoftwareControlledHamRadio@...
Sent: Tuesday, April 19, 2016 7:13 AM
Subject: [SoftwareControlledHamRadio] Re: Capacitor for the LC Circuit is a 56pF
?
Where can I purchase the 22uf inductor.. I doub't my local radio shack has these..I know I can most likely get the 56pf cap from RSbut right now I have the 49'r kit underway and need this one part..
Steve NS3L
|
Re: Capacitor for the LC Circuit is a 56pF
Where can I purchase the 22uf inductor.. I doub't my local radio shack has these..I know I can most likely get the 56pf cap from RSbut right now I have the 49'r kit underway and need this one part..
Steve NS3L
|
Re: 49-er D882 Output Transistor Smoked
Hi Dennis... and thanks for the reply. I actually discovered this sad fact last night. The weather in my neck of the woods has been too nice the past few days to do any experimenting, but I hooked up my scope and checked it. Wow! The reason I didn't use the scope in the first place is that the trace is a little too blurry to be much use and trying to measure voltages on it is not very accurate. I figured the RF probe was a safer bet. Lesson learned. I'm actually glad this happened because it gave me some much needed cautions to put into the manual I'm writing on assembling and testing the radio for our club's class.?
I also think it's time to rebuild my scope. :-)
I ordered about 24 new D882s just in case we run into this problem again especially with newer, more inexperienced hams in the class who are going to build the radio.
Aaron - N2HTL
?
Aaron,
I think you definitely over drove the PA!
Typically, an RF probe is a half-wave rectifier.? If you are trying to measure the peak-to-peak voltage, the best way is with an o'scope.? With the RF probe you would see the RMS value. Of course, you can convert the RMS value to peak-to-peak.
So, by my reckoning, if you measured 4 V on your VTVM, your J3 output would have been roughly 11.3 V p-p; a little bit more than required!? So, I'd say you would have been overdriving the D882.
73,
-dennis W6DQ Inyokern CA
?
Evening all.? Some troubling news... but I want to bring it up to the group in the hopes that the same problem can be avoided for others building the radio.
I've had my DDS controlled 49-er on the air now for the past week and have been making dozens of contacts with it. Fired it up this evening and called CQ a few times. Suddenly, a sharp "pop" came from the board and the D882 started smoking like crazy. Powered the radio down, and sure enough, the D882 is bulged out in a tiny area and looks quite charred. Now it's off to find a replacement... but first, a few questions.
I noticed last night that the D882 was quite hot to the touch. I was thinking about putting a heat sink on it, but it was late and never got around to it. Would a heat sink be almost a requirement for that transistor - especially if the failure was caused by overheating?
When I followed the instructions to adjust R1 on the DDS board to achieve a peak-to-peak voltage of 4 volts, I made the measurement using my VTVM and an RF probe. I connected the probe to J3, and the ground strap of the probe to the ground pin to the left of J3. When I first took a reading, I was getting around 2 volts... so I adjusted R1 until the VTVM was dead on 4 volts. Was adjusting for 4 volts using an RF probe incorrect? Should I have used a scope instead? I'm just wondering if I was actually overdriving the D882 because my measurement was way off.
Would like to avoid this happening again for obvious reasons.... especially if we're going to be teaching a class with this project. :-)
Aaron - N2HTL
|
Re: 49-er D882 Output Transistor Smoked
Aaron,
I think you definitely over drove the PA!
Typically, an RF probe is a half-wave rectifier.? If you are trying to measure the peak-to-peak voltage, the best way is with an o'scope.? With the RF probe you would see the RMS value. Of course, you can convert the RMS value to peak-to-peak.
So, by my reckoning, if you measured 4 V on your VTVM, your J3 output would have been roughly 11.3 V p-p; a little bit more than required!? So, I'd say you would have been overdriving the D882.
73,
-dennis W6DQ Inyokern CA
From: "aaronhev@... [SoftwareControlledHamRadio]"
To: SoftwareControlledHamRadio@...
Sent: Friday, April 15, 2016 7:06 PM
Subject: [SoftwareControlledHamRadio] 49-er D882 Output Transistor Smoked
?
Evening all.? Some troubling news... but I want to bring it up to the group in the hopes that the same problem can be avoided for others building the radio.
I've had my DDS controlled 49-er on the air now for the past week and have been making dozens of contacts with it. Fired it up this evening and called CQ a few times. Suddenly, a sharp "pop" came from the board and the D882 started smoking like crazy. Powered the radio down, and sure enough, the D882 is bulged out in a tiny area and looks quite charred. Now it's off to find a replacement... but first, a few questions.
I noticed last night that the D882 was quite hot to the touch. I was thinking about putting a heat sink on it, but it was late and never got around to it. Would a heat sink be almost a requirement for that transistor - especially if the failure was caused by overheating?
When I followed the instructions to adjust R1 on the DDS board to achieve a peak-to-peak voltage of 4 volts, I made the measurement using my VTVM and an RF probe. I connected the probe to J3, and the ground strap of the probe to the ground pin to the left of J3. When I first took a reading, I was getting around 2 volts... so I adjusted R1 until the VTVM was dead on 4 volts. Was adjusting for 4 volts using an RF probe incorrect? Should I have used a scope instead? I'm just wondering if I was actually overdriving the D882 because my measurement was way off.
Would like to avoid this happening again for obvious reasons.... especially if we're going to be teaching a class with this project. :-)
Aaron - N2HTL
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Re: DDS VFO TXOffset Function
Nope...I never got around to that. I'm hoping someone in this group might run with it, as I have other projects I want to get to.
Jack, W8TEE
From: "robert.vogelpohl@... [SoftwareControlledHamRadio]"
To: SoftwareControlledHamRadio@...
Sent: Sunday, April 17, 2016 9:13 PM
Subject: [SoftwareControlledHamRadio] DDS VFO TXOffset Function
?
This question is most likely for Jack W8TEE. I have my DDS VFO and 49er assembled and all appears to be working correctly. I have a question about the tx offset function. I do not observe any frequency output? change when the J1-24 pin of the DDS VFO board is changed from low to high or vice versa. Is this fully implemented in the Arduino code?
73
Bob - NR7A
?
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DDS VFO TXOffset Function
This question is most likely for Jack W8TEE. I have my DDS VFO and 49er assembled and all appears to be working correctly. I have a question about the tx offset function. I do not observe any frequency output? change when the J1-24 pin of the DDS VFO board is changed from low to high or vice versa. Is this fully implemented in the Arduino code? 73 Bob - NR7A ?
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49-er D882 Output Transistor Smoked
Evening all.? Some troubling news... but I want to bring it up to the group in the hopes that the same problem can be avoided for others building the radio.
I've had my DDS controlled 49-er on the air now for the past week and have been making dozens of contacts with it. Fired it up this evening and called CQ a few times. Suddenly, a sharp "pop" came from the board and the D882 started smoking like crazy. Powered the radio down, and sure enough, the D882 is bulged out in a tiny area and looks quite charred. Now it's off to find a replacement... but first, a few questions.
I noticed last night that the D882 was quite hot to the touch. I was thinking about putting a heat sink on it, but it was late and never got around to it. Would a heat sink be almost a requirement for that transistor - especially if the failure was caused by overheating?
When I followed the instructions to adjust R1 on the DDS board to achieve a peak-to-peak voltage of 4 volts, I made the measurement using my VTVM and an RF probe. I connected the probe to J3, and the ground strap of the probe to the ground pin to the left of J3. When I first took a reading, I was getting around 2 volts... so I adjusted R1 until the VTVM was dead on 4 volts. Was adjusting for 4 volts using an RF probe incorrect? Should I have used a scope instead? I'm just wondering if I was actually overdriving the D882 because my measurement was way off.
Would like to avoid this happening again for obvious reasons.... especially if we're going to be teaching a class with this project. :-)
Aaron - N2HTL
|
Thanks Norbert,
My question is: Is the green one the same characteristics as the black core. I searched for a green ferrite color code and it doesn¡¯t track to the specified type.
73
Gary
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Hi Gary!
I had the same experience with mine.?
The?red is red?and the?green?is the one they refer as?black.?
L3 = Green core 11 turns
L4 = Red core 16
turns? Check the "49er Inductor windings"?post from Apr 5 for more details.?
73s Norbert ?
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My 49er kit came with a red and a green ferrite core. Has anyone else had the same experience for L3 (green not black), and does the green core seem to work for L3? 73 Gary W5GW
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Running on LiOn Batteries
Hi!
Quick update,?I hot glued a battery holder to my case and I'm getting around 12.6 volts (fully charged) with three 18650 LiOn batteries. I believe these are rated 3000mah (Samsung ICR18650-30B). ?The output power is 2 point something almost 3 watts according to the meter on my MFJ tuner. The battery holder came from our friends at eBay and the LiOns from a Dell Laptop battery.
Also added a power switch in the back. This thing is sweet !?
73s Norbert
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jjpurdum