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7.8MHz? Ouch...ok, something is wrong then...

You shouldn't get any that low - you're out of the Crystals passband...

It could be one of many reasons why you don't have any audio ... out of the filter range the AN612 is set up for.

Remember the VR4 Carrier Balance - its' an offset voltage ADDED to the audio - as a bias to push up or down the zero-beat frequency of the audio wave. The Zero point. It works as if you "center" the audio in SSB, but the AN612 and the way it works with AM - you don't send audio into the AN612 when you're in AM mode, just what is on Pin 3 from the PLL / IF and that's flat out 10.690MHz the center of the channels' frequency. Audio applied to Pin 1 adds or subtracts from that frequency (your positive non-inverted and negative inverted) depending on your SSB mode select USB or LSB - AM is center.

So TP5 should have shown you 10.69MHz (If any - D9 acts as an RF switch to turn off this section so it doesn't interfere with the AM detector - again powered by AM mode that powers TR19) - the purpose of TP 5 is because that is where the CONVERSION occurs for SSB, but when you use AM mode, you don't need the conversion - you have the detector - and that is where TR19 comes into play - grounds out audio in and sets up the detector in AM mode. But TP5 is from the CLARIFIER side (audio side) of the IF that mixes with the 17MHz from the PLL You'd see that, at the AN7310 the TX mixer on the side rail by the Pre-Driver . So that would only be BETWEEN USB (10.7) and LSB (10.65) - TP 9 is AM - that should be your 10.69 - that test point is D14, between FT1 (that BIG metal Filter can) and the AN612 - close to the PLL and VR 4.

TR19 needs to keep Pin 1 low so it doesn't drift off into neverland - so look back and locate that JV jumper for TR19 - the one that turns it on - and make sure it works and pull and check/test TR19 - good/bad - act accordingly.

<blockquote data-quote="Handy Andy" data-source="post: 645315" data-attributes="member: 52309">7.8MHz? Ouch...ok, something is wrong then...You shouldn&#039;t get any that low - you&#039;re out of the Crystals passband...It could be one of many reasons why you don&#039;t have any audio ... out of the filter range the AN612 is set up for.Remember the VR4 Carrier Balance - its&#039; an offset voltage ADDED to the audio - as a bias to push up or down the zero-beat&nbsp; frequency of the audio wave. The Zero point. It works as if you &quot;center&quot; the audio in SSB, but the AN612 and the way it works with AM - you don&#039;t send audio into the AN612 when you&#039;re in AM mode, just what is on Pin 3 from the PLL / IF and that&#039;s flat out 10.690MHz the center of the channels&#039; frequency.&nbsp; Audio applied to Pin 1 adds or subtracts from that frequency (your positive non-inverted and negative inverted) depending on your SSB mode select USB or LSB - AM is center.So TP5 should have shown you 10.69MHz (If any - D9 acts as an RF switch to turn off this section so it doesn&#039;t interfere with the AM detector - again powered by AM mode that powers TR19) - the purpose of TP 5 is because that is where the CONVERSION occurs for SSB, but when you use AM mode, you don&#039;t need the conversion - you have the detector - and that is where TR19 comes into play - grounds out audio in and sets up the detector in AM mode. But TP5 is from the CLARIFIER side (audio side) of the IF that mixes with the 17MHz from the PLL&nbsp; You&#039;d see that, at the AN7310 the TX mixer on the side rail by the Pre-Driver . So that would only be BETWEEN USB (10.7) and LSB (10.65) - TP 9 is AM - that should be your 10.69 - that test point is D14, between FT1 (that BIG metal Filter can) and the AN612 - close to the PLL and VR 4.TR19 needs to keep Pin 1 low so it doesn&#039;t drift off into neverland - so look back and locate that JV jumper for TR19 - the one that turns it on - and make sure it works and pull and check/test TR19 - good/bad - act accordingly.</blockquote>

[QUOTE="Handy Andy, post: 645315, member: 52309"] 7.8MHz? Ouch...ok, something is wrong then... You shouldn't get any that low - you're out of the Crystals passband... It could be one of many reasons why you don't have any audio ... out of the filter range the AN612 is set up for. Remember the VR4 Carrier Balance - its' an offset voltage ADDED to the audio - as a bias to push up or down the zero-beat frequency of the audio wave. The Zero point. It works as if you "center" the audio in SSB, but the AN612 and the way it works with AM - you don't send audio into the AN612 when you're in AM mode, just what is on Pin 3 from the PLL / IF and that's flat out 10.690MHz the center of the channels' frequency. Audio applied to Pin 1 adds or subtracts from that frequency (your positive non-inverted and negative inverted) depending on your SSB mode select USB or LSB - AM is center. So TP5 should have shown you 10.69MHz (If any - D9 acts as an RF switch to turn off this section so it doesn't interfere with the AM detector - again powered by AM mode that powers TR19) - the purpose of TP 5 is because that is where the CONVERSION occurs for SSB, but when you use AM mode, you don't need the conversion - you have the detector - and that is where TR19 comes into play - grounds out audio in and sets up the detector in AM mode. But TP5 is from the CLARIFIER side (audio side) of the IF that mixes with the 17MHz from the PLL You'd see that, at the AN7310 the TX mixer on the side rail by the Pre-Driver . So that would only be BETWEEN USB (10.7) and LSB (10.65) - TP 9 is AM - that should be your 10.69 - that test point is D14, between FT1 (that BIG metal Filter can) and the AN612 - close to the PLL and VR 4. TR19 needs to keep Pin 1 low so it doesn't drift off into neverland - so look back and locate that JV jumper for TR19 - the one that turns it on - and make sure it works and pull and check/test TR19 - good/bad - act accordingly. [/QUOTE]

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