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Even the Martians are feeling it
If you are having problems with the bands, so are the hams on Mars. It appears that even ET8 has been affected. Here is probably the reason. Epic solar storm effects seen by Mars rovers
By HOWARD POMERANTZ · #9638 ·
Friday
I plan to be at the Baylands starting with lunch. Hope to see many of you. Hiroki AH6CY
By Hiroki Kato · #9637 ·
Re: TruSDX FTW
I wouldn't discourage you from adding it. If it shorts, it's easier to replace than a FET, cheaper too. --Jeff [email protected]> wrote:
By Jeff Reagan · #9636 ·
Re: The Joy of Six
I've been in chester the past several weeks, and the blustery winds kept me from putting up antennas.? The road thru lassen is not yet plowed, so no hf or vhf ops for me.?? As Cliff mentioned,
By Eric · #9635 ·
Re: The Joy of Six
Last Saturday during the VHF contest I heard some ops on 2m QSY to 6m, fm, 52.525. so that's 2. Otherwise, yeah all the action is FT8, 50.313. no CW, SSB, AM. Shame, waste of 4MHz. Contest wise, the
By Cliff Sojourner K6CLS · #9634 ·
Re: TruSDX FTW
And can anyone give me a reason not to install the diode?? I'm trying to learn
By Doug Hendricks · #9633 ·
Re: TruSDX FTW
The diode is between drain and source on fet.? Source is ground.can you explain why it works??
By Doug Hendricks · #9632 ·
Re: TruSDX FTW
There are two different mechanisms for reverse breakdown in diodes: zener and avalanche.? Generally diodes with low reverse breakdown are in the zener mode and diodes with higher breakdown voltages
By Paul AA6PZ · #9631 ·
Re: TruSDX FTW
It gets back to the question: is the Avalanche Breakdown characteristic of the FET more delicate than that of a 1 watt zener. Maybe the 1 watt zener is tougher than the FET. Counterintuitive results
By Jeff Reagan · #9630 ·
Re: TruSDX FTW
The zener in the video is connected across the FET, between source and drain. That zener is definitely not subjected to RF AC output voltage. [email protected]> wrote:
By Jeff Reagan · #9629 ·
Re: TruSDX FTW
Doesn't Hiroki's video disprove that?
By Doug Hendricks · #9628 ·
Re: TruSDX FTW
There's another possibility: the zener is so weak, it blows open the instant the transmitter comes on. [email protected]> wrote:
By Jeff Reagan · #9627 ·
Re: TruSDX FTW
Here is an empirical proof to show how a single 1N4756 zener diode actually protects against high SWR. I ordered a bag of 10 1N4756As. I won¡¯t need all of them. Anyone who needs one would be welcome
By Hiroki Kato · #9626 ·
Re: TruSDX FTW
There are pictures of both rigs with diode installed at the beginning of this thread.
By Doug Hendricks · #9625 ·
Re: TruSDX FTW
My guess is, it isn't across the RF output. [email protected]> wrote:
By Jeff Reagan · #9624 ·
Re: TruSDX FTW
Guys, first of all I am not an engineer.? ?Please go to trusdx forum and do a search for 1n4756a.? Read the posting by Sars.? He says no I'll effects, i.e. spurious or harmonics generated.? ?Our
By Doug Hendricks · #9623 ·
Re: TruSDX FTW
Oops. I tend to give people the benefit of the doubt. It begs the question, where was that zener really connected? [email protected]> wrote:
By Jeff Reagan · #9622 ·
Re: The Joy of Six
I built a 6 meter rig back in high school.? I had a WA8 call and collected QSL cards from 20 states.? Then I move to CA and channel 2 TV brought that to an end. Last year, I got motivated to get
By Paul AA6PZ · #9621 ·
Re: TruSDX FTW
I totally agree.? With the one diode as originally proposed, it would clip the waveform and generate harmonics.
By Paul AA6PZ · #9620 ·
Re: TruSDX FTW
Cooy and paste from above: " I? strongly encourage you to install a 1N4756A diode between rf and ground."
By David · #9619 ·