Hi,
I finished my (tr)uSDX and installed the firmware. Selecting bands is working. But after powering with USB I notice that the BS170 are getting hot already in receive mode.
What can be the problem?
Thanks for your help!
Regards,
Anton
BS170's get very hot in receive mode
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Re: BS170's get very hot in receive mode
BS170´s dead or soldered in reversed.
There are BS170s with wrong pin outs. Even the datasheets contradict each other.
Exchange BS170s and watch for right pin order.
73 Manuel; DL2MAN
There are BS170s with wrong pin outs. Even the datasheets contradict each other.
Exchange BS170s and watch for right pin order.
73 Manuel; DL2MAN
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- Posts: 20
- Joined: 23 May 2022, 10:44
Re: BS170's get very hot in receive mode
Thanks Manuel,
I ordered a batch of BS170's, will swap them this weekend.
73,
Anton
I ordered a batch of BS170's, will swap them this weekend.
73,
Anton
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- Joined: 23 May 2022, 10:44
Re: BS170's get very hot in receive mode
Dumb question; I removed the BS170’s, before replacing them one check; can I receive without those FET’s?
73,
Anton
73,
Anton
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- Joined: 30 Dec 2021, 19:18
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Re: BS170's get very hot in receive mode
Thanks! Replaced the FET’s, not hot this time. But still no reception, same noise with or without RF board. Sending on USB power states power 0.24W and a SWR of 9.99. The first is to be expected, the last is the next thing to fix. I will use a signal generator and follow the signal from the antenna port with my oscilloscope further along the board.
73,Anton
73,Anton
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- Posts: 20
- Joined: 23 May 2022, 10:44
Re: BS170's get very hot in receive mode
Reception is OK now, replaced the T1/T2, (2/14). Still low power TX. Replaced the 3 BS170 again,
no results. Removed them, I measure ~2.45V DC on Gate, 12.6V Drain. Is this oké?
Placed another first BS170, power on; "Fireworks".
Up to the next batch of FET's..
no results. Removed them, I measure ~2.45V DC on Gate, 12.6V Drain. Is this oké?
Placed another first BS170, power on; "Fireworks".
Up to the next batch of FET's..
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- Posts: 20
- Joined: 23 May 2022, 10:44
Re: BS170's get very hot in receive mode
After buying a component tester I found 1 explanation of the problem; my complete stock of BS170’s are fakes. (Not those 3 from the kit, I broke them due to a short)
https://twitter.com/antonrietveld/statu ... 8TSUC4iHww
I have to order somewhere the real thing
73,Anton
https://twitter.com/antonrietveld/statu ... 8TSUC4iHww
I have to order somewhere the real thing
73,Anton
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- Posts: 20
- Joined: 23 May 2022, 10:44
Re: BS170's get very hot in receive mode
Yes! Finally got it working, FET’s from QRP Labs; first QSO yesterday with End-Fed ~1000KM to Slovenia on 20 mtr. Today efficiency check: 4,76W 88,46% eff. on 40 mtr. on End-Fed
Manuel Thanks!
Anton - PD5ANT, 73
Manuel Thanks!
Anton - PD5ANT, 73
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