* RX strangeness on a SBE Console 6 base help *

[Retro CB Guy]

Hi - Yeah I've got this very strange recieve issue going on with a SBE Console 6 where the RX is more than a HOT reciever LOL...

No antenna with a 9 S units of white noise (all modes yes) type of stuff which is insane and just weird. So I thought posting here, some of you good folks/techs could comment with some ideas and more hopefully, as to what this could be going on with this very nice for it's age and recapped algined etc base of mine! Looking to resolve this totally...

Thanks in advance 73's happy skip shooting, Retro

 

[Klondike Mike]

Give us some more details about the "recapped algined ..." part of your post. First question that comes to mind is how does one do a RX/TX alignment with a S9 level of noise? As you step through through the procedure, (next question, what procedure was followed and was appropriate test equipment used?), the first section to fail is a good place to stop and start studying the schematic. I'm just a hobbyist who sells capacitor kits, the PRO's will chime in later with more concentrated directions depending on your additional information you are able to provide.

 

[Retro CB Guy]

Give us some more details about the "recapped algined ..." part of your post. First question that comes to mind is how does one do a RX/TX alignment with a S9 level of noise? As you step through through the procedure, (next question, what procedure was followed and was appropriate test equipment used?), the first section to fail is a good place to stop and start studying the schematic. I'm just a hobbyist who sells capacitor kits, the PRO's will chime in later with more concentrated directions depending on your additional information you are able to provide.

Hi Mike, Yes sir good questions! Well the tech has been doing this for decades, has all the proper equipment, is meticulous with it or prefers to get it right before sending it back to me, but what happened was when I got it back shipped from a few states from me it had this RX problem and wasn't doing that when he had it...

Bought CAPS from you sir 73, Retro

 

[nomadradio]

Does the RF Gain control have any effect? Do signals from the antenna overload and distort the audio?

73

 

[Retro CB Guy]

Does the RF Gain control have any effect? Do signals from the antenna overload and distort the audio?

73

Hi Chris, Good to see you here! Rf gain does affect it. So we know it's before that stage. Signals from antenna do not audibly overload or audibly distort the audio.

73's, Retro

 

[b2cooll]

That is odd for sure, I have seen transistors get noisy but 9S is very odd. If the RF gain takes it out then you have to work backwards from there, so maybe pull the pass thru cap between stages until it's gone. Now knowing you my friend... you have a DDS setup in that rig to get more channels right? if so that could be oscillating or bleeding into the RX, what does the RX sound like ( type of noise ) and is it the same on AM and SSB? and try the rig on a external DC power supply

 

[Retro CB Guy]

That is odd for sure, I have seen transistors get noisy but 9S is very odd. If the RF gain takes it out then you have to work backwards from there, so maybe pull the pass thru cap between stages until it's gone. Now knowing you my friend... you have a DDS setup in that rig to get more channels right? if so that could be oscillating or bleeding into the RX, what does the RX sound like ( type of noise ) and is it the same on AM and SSB? and try the rig on a external DC power supply

Hopefully these three videos I have attached will upload and people can get some more information that way and even one of the short clips shows the difference with the HF receiver regarding this issue, which it doesn't affect that much if any. I think I tried it on DC power but I'm not sure but I will certainly have the technician that has it now check it ASAP which will likely be the next coming weekend if he hasn't did it already, trying to remember...

Many thanks for replying 73's, Retro

 

[b2cooll]

I would say it's from the mixers maybe one of the IF's is to strong & overloading the mixer or notch filter as those are a add/subtract kind of thing. Thats a guess as I am thinking the DDS replaces one of the IF's. These maiboards have the same offset on AM & USB with LSB being 3kc lower (clue). Also that board uses a doubler circuit I believe on the 10 MHz Ref. I use the Craig L131 manual at times. This is the PLL sch to help