[ARC5] Lopsided modulation

[AKLDGUY .]

Hi Q antenna? Maybe. It's an end-fed wire just over 1/8 wavelength long at
75m. Runs around the top of my 6 foot high fence, taking a dog leg at one
place and a 90 degree turn at another. But how come my friend is
experiencing the same, but he has a full size inverted Vee?

Neil ZL1ANM

On 25/02/2018 11:15 AM, "Tim" <timsamm at gmail.com> wrote:

> Hi Neil - Are you using a very "high Q" antenna system somehow?  Tuned to
> your carrier or what is your stronger sideband - thus attenuating the
> "wimpy" sideband?  I dunno, just a guess...
> Glad to hear you have them on the air!
>
> Tim
> N6CC
>
> On Sat, Feb 24, 2018 at 2:07 PM, AKLDGUY . <neilb0627 at gmail.com> wrote:
>
>> FM does not seem to be present in either his signal or mine. The carriers
>> are straight lines on the waterfall display. Actually, there is one
>> operator on the net whose carrier is a fuzzy line when he speaks, but his
>> sidebands are symmetrical. I'm stumped.
>>
>> Neil ZL1ANM
>>
>> On 25/02/2018 10:30 AM, "Richard Knoppow" <1oldlens1 at ix.netcom.com>
>> wrote:
>>
>>>     That affects the upward vs downward modulation but not the strength
>>> of the sidebands. A frequent cause of asymetrical sidebands is incidental
>>> FM. If the oscillator is being affected by the modulation it can be the
>>> cause.
>>>     The scope display will not show assymetry of the upper vs lower
>>> sidebands although it will certainly show assymetry of upward vs downward
>>> modulation.
>>>
>>> On 2/24/2018 1:18 PM, Jim Wiley wrote:
>>>
>>>> One reason could be that your voice in itself is non-symmetrical.  If
>>>> you can do so easily, try reversing the "polarity" if the modulation
>>>> transformer, and see if that helps.  If it does, your can leave it set the
>>>> way that works best for you. Monitoring the modulation envelope with an
>>>> oscilloscope is always  the best way.
>>>>
>>>> - Jim, KL7CC
>>>>
>>>>
>>>>
>>>> On 2/24/2018 11:38 AM, AKLDGUY . wrote:
>>>>
>>>>> A friend and I are running Command transmitters on the local 75 meter
>>>>> AM net, with full plate and screen modulation. We monitor our transmissions
>>>>> on the local SDR receiver site which has a waterfall display. In both
>>>>> cases, the lower sideband shows as considerably stronger than the upper,
>>>>> and this has us perplexed. Our stations are the only ones affected.
>>>>>
>>>>> I have never seen anything in the literature to explain this. Downward
>>>>> modulation is a problem with AM, but articles do not indicate whether
>>>>> lopsided modulation results.
>>>>>
>>>>> My transmitter is the AN/ARC-5, absolutely unmodified and running 40W
>>>>> input due to dynamotor constraint. His is the SCR-274 modified for plate &
>>>>> screen modulation and running twice that.
>>>>>
>>>>> Anyone suggest a reason for the unequal sidebands?
>>>>>
>>>>> Neil ZL1ANM
>>>>>
>>>>
>>>
>>> --
>>> Richard Knoppow
>>> 1oldlens1 at ix.netcom.com
>>> WB6KBL
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