Ground loop city. That's the cause of your ills and hum. Not a uncommon
issue with most ham station wiring and grounding. I don't consider it luck.
It is simply proper planning and correct grounding techniques applied
This says your station ground and AC mains ground are not bonded together
thus a difference in potential exists as you discovered. A great invitation
for lightning damage from a nearby strike. The RS transformer simply breaks
the ground loop but does nothing to provide proper grounding.
If you wish, I'll send you a paper on Lightning Protection for the Home and
the Station. Many ham stations are dangerously grounded. A separate E-Mail
request will get you the Microsoft Word document. It's about 128K in size.
73
Bob, K4TAX
----- Original Message -----
From: "joel hallas" <jrhallas@optonline.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Sunday, May 29, 2005 6:35 AM
Subject: Re: [TenTec] Omni vi plus input audio feed for psk
> Bob,
>
> You may be very lucky! With my Paragon (line out) to sound card input I
> had a very loud hum on SSB xmit (I know that's the other side <g>), even
> when the computer was off.
>
> In my station, I have separate power feeds for radio equipment and other
> stuff and it appears that there was a sufficient difference in "green
> wire" ground voltage to cause a hum.
>
> By putting a RS isolation transformer in that lead it took care of the
> problem, for $1.75, I think. BTW, the transmit side was isolated in the
> Rigblaster, or likely would have had the same problem.
>
> Regards, Joel, W1ZR
>
> Robert & Linda McGraw K4TAX wrote:
>
>>Denton:
>>
>>First, the transformer may be "ringing" with square wave signals as a
>>result
>>of the transformer secondary not being correctly loaded.
>>
>>At my station, I connect direct from the sound card line IN/OUT to the
>>Audio
>>In / Audio Out of the Omni VI+. No problem in adjusting levels with the
>>Mixer settings of the sound card and the MIC gain on the Omni VI+ runs
>>about
>>9 o'clock which is normal. I use VOX to do the switching and get great
>>reports at about 35 to 45 watts output.
>>
>>I find that most folks "over engineer" the project.
>>
>>73
>>Bob, K4TAX
>>
>>----- Original Message -----
>>From: "denton" <denton@oregontrail.net>
>>To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
>>Sent: Saturday, May 28, 2005 6:36 PM
>>Subject: [TenTec] Omni vi plus input audio feed for psk
>>
>>
>>
>>
>>>I am currently using my omni vi plus for psk, with the output of the
>>>soundcard going to an audio transformer to give me a good match to the
>>>audio
>>>input jack in the back of my Omni....on the air reports indicated good
>>>imd
>>>at 40 watts out of the rig at -31, but sometimes I get a ringing report
>>>and
>>>indication of minor sidebars.
>>>What I want to do is bypass the mic audio amp to give me much better
>>>linearity for the various soundcard modes.
>>>>From examining the schematic and its adjoining criteria, it seems that I
>>>
>>>
>>>>can
>>>>
>>>>
>>>feed the audio out from the soundcard directly to the input of the
>>>balanced
>>>modulator, with appropriate filtering and limit the output of the rig to
>>>about 35 watts or so.
>>>Any thoughts on this?? thanks...
>>>----- Original Message -----
>>>From: "John L Merrill" <jmerrill1@adelphia.net>
>>>To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
>>>Sent: Saturday, May 28, 2005 4:03 PM
>>>Subject: Re: [TenTec] SSB recieve audio?
>>>
>>>
>>>
>>>
>>>>I have a MkV Field and an FT1000D and with internal or external speaker
>>>>they sound better to my inner or outer ears than my on the chopping
>>>>block Orion with external and internal speaker. The OmniVI+ with the
>>>>audio mod in it sounds better than an Orion.
>>>>
>>>>John N1JM
>>>>
>>>>denton wrote:
>>>>
>>>>
>>>>>Wonder how the Orion's SSB audio sounds compared to an Omni VI??
>>>>>For some reason, to my ears, my FT990 seems to sound better than my
>>>>>Omni
>>>>>VI
>>>>>on ssb.
>>>>>----- Original Message -----
>>>>>From: "John L Merrill" <jmerrill1@adelphia.net>
>>>>>To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
>>>>>Sent: Saturday, May 28, 2005 2:51 PM
>>>>>Subject: Re: [TenTec] Propm RX
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>>I have an R4A I've been repairing here on the bench and with the same
>>>>>>speaker, it sounds better than the Orion :-).
>>>>>>
>>>>>>John N1JM
>>>>>>
>>>>>>Grant Youngman wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>>>I agree. The receive audio is lousey on the Orion.
>>>>>>>>
>>>>>>>>
>>>>>>>Maybe you just need a decent speaker. Or perhaps your inner ear
>>>>>>>needs
>>>>>>>some
>>>>>>>work :-)
>>>>>>>
>>>>>>>The Orion has excellent SSB receive audio, as good or better than any
>>>>>>>HF
>>>>>>>rig
>>>>>>>I've used (many, new and old), and generally requires little in the
>>>>>>>way
>>>>>>>of
>>>>>>>receive EQ. I do much prefer it with a little more than the usual
>>>>>>>bandwidth
>>>>>>>(say around 3 Khz or so), but that's no different than most radios
>>>>>>>which
>>>>>>>sound like cr*p at the typical narrow bandwidths everyone want to
>>>>>>>use.
>>>>>>>
>>>>>>>Of course, it would benefit greatly from a pair of P-P 6V6's in the
>>>>>>>output
>>>>>>>stage, but I doubt that's in the plan :-)
>>>>>>>
>>>>>>>Grant/NQ5T
>>>>>>>
>>>>>>>
>>>>>>>_______________________________________________
>>>>>>>TenTec mailing list
>>>>>>>TenTec@contesting.com
>>>>>>>http://lists.contesting.com/mailman/listinfo/tentec
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>_______________________________________________
>>>>>>TenTec mailing list
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>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>_______________________________________________
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>>>>>
>>>>>
>>>>>
>>>>_______________________________________________
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>>>>
>>>>
>>>>
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>>>
>>>
>>
>>
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>>
>
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