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I have been contacting a bunch of different folks that repair radios. So far I have only found two that will even talk to me about the SSB modulation issue I am having on my Q5N2 but it's a start. Note that the radio did not come with this issue. I believe it's a self-inflicted byproduct of most likely a station issue or less likely an amp issue. I'm treating it as the former until I eliminate everything I can on this end of things.

One of the techs asked me the following:

Have you measured the bias voltage on the IRF520 gate lead(s)? It should be about 3.5 Volts on SSB with mic keyed and no modulation/audio.

I have not yet but I want to. However, I am not sure how to safely do this.

Do I connect the DIMM's positive to gate and negative to source? Do I perform the bias voltage test on all four IRF520s that are in the Q5N2?

<blockquote data-quote="TimmyTheTorch" data-source="post: 811745" data-attributes="member: 64271">I have been contacting a bunch of different folks that repair radios. So far I have only found two that will even talk to me about the SSB modulation issue I am having on my Q5N2 but it&#039;s a start. Note that the radio did not come with this issue. I believe it&#039;s a self-inflicted byproduct of most likely a station issue or less likely an amp issue. I&#039;m treating it as the former until I eliminate everything I can on this end of things.One of the techs asked me the following:Have you measured the bias voltage on the IRF520 gate lead(s)? It should be about 3.5 Volts on SSB with mic keyed and no modulation/audio.I have not yet but I want to. However, I am not sure how to safely do this.Do I connect the DIMM&#039;s positive to gate and negative to source? Do I perform the bias voltage test on all four IRF520s that are in the Q5N2?</blockquote>

[QUOTE="TimmyTheTorch, post: 811745, member: 64271"] I have been contacting a bunch of different folks that repair radios. So far I have only found two that will even talk to me about the SSB modulation issue I am having on my Q5N2 but it's a start. Note that the radio did not come with this issue. I believe it's a self-inflicted byproduct of most likely a station issue or less likely an amp issue. I'm treating it as the former until I eliminate everything I can on this end of things. One of the techs asked me the following: [B][I]Have you measured the bias voltage on the IRF520 gate lead(s)? It should be about 3.5 Volts on SSB with mic keyed and no modulation/audio.[/I][/B] I have not yet but I want to. However, I am not sure how to safely do this. Do I connect the DIMM's positive to gate and negative to source? Do I perform the bias voltage test on all four IRF520s that are in the Q5N2? [/QUOTE]

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