Smoke Test

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Smoke Test

Postby KC3OL » Thu Mar 13, 2003 5:58 pm

I have completed construction of my 80 meter 6 fet transmitter and will begin smoke testing on Sunday. Wish me luck.

Ted, KC3OL
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Smoke Test

Postby Phil G4ZOW » Fri Mar 14, 2003 4:45 am

Should I stay down in the bunker Ted?

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smoke test

Postby ke1gf » Fri Mar 14, 2003 3:48 pm

I had my maden voyage of mine on monday... I had problems with my driver on tuesday when I tried a different length of coax between the rice box and the transmitter and ended up losing 6 fets... I wasn't using the over-current circuit but I'm going to add it in when my new fets come in so it doesn't happen again!

Best of luck on your transmitter...
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ouch

Postby k3xf » Fri Mar 14, 2003 9:20 pm

I am using a 6 amp max supply with regular fuses for now. . .'will keep your experience in mind while building the driver stage. . .
-ap
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Postby KC3OL » Sat Mar 15, 2003 1:02 pm

I fired up my 80 meter transmitter and had everything working fairly well. Power out is only 150 watts and I don't know why it is low. The modulator was working just fine and I could easily modulate the rig over 100%.
While I was making some measurements I accidently shorted the 10 Amp 200 volt diode on the modulator board and it it instantly wiped out half of the mosfets on the modulator board along with the .5 ohm resistors.
I'm feeling bummed out right now and have placed a new order with Mouser and Digikey to get replacement parts.
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Don't Let The Smoke Out!

Postby Brent » Tue Mar 18, 2003 12:13 am

Good Luck Ted :) I am hoping to get mine one the air in another month.
Been getting lots of help from Steve/QIX, Blaine/GTU, Bob/KBW and others. I have been bitten by the bug to build as Bob put it and he's right.

Pics to follow maybe tommorow as a work in progress.

73 Brent W1IA
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Did the overload shutdown not work correctly?

Postby steve_qix » Tue Mar 18, 2003 7:13 am

KC3OL wrote:While I was making some measurements I accidently shorted the 10 Amp 200 volt diode on the modulator board and it it instantly wiped out half of the mosfets on the modulator board along with the .5 ohm resistors.


Hi Ted,

How could that possibly have happened? I could possibly see blowing one FET (unlikely as this may be), but 6 of them?

Is your overload circuit working properly? The relays should have removed the power way before anything blew.

Let me know :-)

Regards,

Steve
Visit the class E web site at:

http://www.classeradio.com
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It's up and running!!

Postby KC3OL » Thu Mar 20, 2003 8:50 pm

:lol:
I put my new rig on the air for the first time this evening and everyone says it sounds GREAT. I am running it at 250 watts output but am able to get power up to 300 if needed. My drive power is 20 watts. My voltage is running about 46 volts and current measures at 5.4 amps. I know that this can't be correct because 100% efficiency is impossible. I will check the calibration of that meter. I made the shunt from #14 wire. The heat sink for the rf amplifier does not get hot. The heat sink for the modulator gets much warmer and I decided to put a muffin fan on it.
I have a 500 pfd doorknob cap. connected in parallel with my variable loading capacitor and it looks like the amount of loading capacity I am using is about 1000 pfd.
Here are a few photos of the rig:
http://www.kc3ol.dynip.com/downloads/rfamp.jpg
http://www.kc3ol.dynip.com/downloads/rfamp1.jpg
http://www.kc3ol.dynip.com/downloads/rfamp2.jpg

73, Ted
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Postby Glenn K2KL » Fri Mar 21, 2003 12:32 pm

Hi Ted;

Congrats!! Very nice job on that transmitter :D

I just received my rack enclosure for my power supply modulator,
you guys are really motivating me to get my butt in gear!! :!:

Hope to hear you on the air soon!
Glenn K2KL
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Great Job

Postby Brent » Mon Apr 07, 2003 8:53 am

Nice layout...reminds me of Bills (KE1GF) without the power-supply on board....Looking forward to hearing you.

73 Brent W1IA
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