I'm on a vacation now (currently in 9H land) and I brought a (tr)uSDX with me. Somehow, after making a few FT8 contacts with an EFHW off the hotel balcony, I blew my final! (Too bad, because I'm on my way to 4X land for a while after this.) When I get home, I'm definitely going to add a Zener diode to the (tr)uSDX!
So no demonstration of any way how you can repeatably blow a transistor *without* the diode makes this a dubious protection test as the supposed risk is probably not replicated - and having added a random non-linear device no spectrum analysis to see if the power output and LPF action is still clean either Running on a safe supply /voltage, Putting a 3dB pad in line to tune up or an SWR meter on the output generally will probably reduce the BS170 casualty rate equally successfully I have a QCX+5W beacon that has run for 1000's of hours now into a OK-ish antenna and the only casualties have been a Si5351 and a demodulator chip in one single unattended thunderstorm. The BS170's are all originals and still running happily
Its a pity that QDX owners are not seeing this proof - their site is fun to read - all these people complaining about their dead-QDX radios and you have the solution right here, ha ha
![[[OFFICIAL MV]] เอิ้นขวัญให้อ้าย- อ๊ะอาย สกุณาพร | ค่ายเพลงเป็นหนึ่ง](http://i.ytimg.com/vi/83x6L3X3qh0/mqdefault.jpg)
I'm on a vacation now (currently in 9H land) and I brought a (tr)uSDX with me. Somehow, after making a few FT8 contacts with an EFHW off the hotel balcony, I blew my final! (Too bad, because I'm on my way to 4X land for a while after this.) When I get home, I'm definitely going to add a Zener diode to the (tr)uSDX!
What a simple solution, I will have to try this on one of my uSDX's, I missed on on the ADX kits ;-(
So no demonstration of any way how you can repeatably blow a transistor *without* the diode makes this a dubious protection test as the supposed risk is probably not replicated
- and having added a random non-linear device no spectrum analysis to see if the power output and LPF action is still clean either
Running on a safe supply /voltage, Putting a 3dB pad in line to tune up or an SWR meter on the output generally will probably reduce the BS170 casualty rate equally successfully
I have a QCX+5W beacon that has run for 1000's of hours now into a OK-ish antenna and the only casualties have been a Si5351 and a demodulator chip in one single unattended thunderstorm. The BS170's are all originals and still running happily
Many thanks you for sharing, but 1N4756 Power Max - 1.3 W (not 5w) according to Datasheet from Digi-Key. 73!
Its a pity that QDX owners are not seeing this proof - their site is fun to read - all these people complaining about their dead-QDX radios and you have the solution right here, ha ha
How abput trying keying the rig ala cw or something to see if still ok
Good idea Glen! Will try that too.
Adx de uno ya daha bi yakışmış. İyi çalışmalar. 73 de ta2oen
Tesekkurler 😊
I blew up my BS170 at the first press if my PTT. Never know this solution exist.