Sorry, but I just don't "get" it. If you aligned the BFO oscillators
precisely as you say, and you've tried multiple 2.4KHz 9MH i.f. filters, I
don't see why the rig is doing that.
The evidence seems to suggest BFO oscillator misalignment. Oh well.
Barry N1EU
On Sun, Apr 6, 2014 at 12:58 PM, Mark Kenward <k8vf_mark@centurytel.net>wrote:
> Thanks, Ken.
>
> Yes, my first job was to set the bfo's correctly, at least LSB, USB and
> CW transmit...got them within one Hertz. I had to mal adjust the FSK bfo's
> in order to get the other 3 on freq...(neither I nor the friend uses FSK,
> bust uses AFSK, so no worries there. But if I adjusted whichever is first
> in the manual, FSK low, I think, it was impossible to set the CW transmit
> offset, it would be 985 Hz, or some such.
> I chose to set LSB/USB and cw transmit since FSK was not being used.
>
> I set the reference oscillator, and adjusted the passband tuning
> frequencies.
>
> Also set carrier balance.
>
> I tried adjusting the LSB BFO a bit, but as soon as you do that, you are
> off frequency according to the dial frequency.
>
> I even tried replacing the 9mHz 2.4 filter, to no avail, same situation.
>
> I thought of going to WWV on 10 MHz, and setting sideband frequencies the
> same, by using a soundcard scope to show and set according to the 500 and
> other WWV transmitted frequencies. But when I did this, you couldn't
> switch from one sideband to the other and be on frequency..might be 1/2 kHz
> apart, and although they both sounded the same, the dial readout was
> wrong.(and adjusting reference oscillator would just make it off on the
> other bands.
>
> As I had posted earlier, I am within 50 Hz from 160 to 10 meters carrier
> wise, and cw transmit is right on across the bands, dead center in my cw
> filters on my omni 6 PLUS rigs, so it seems isolated to LSB BFO circuit.
> (I was actually hoping there was an adjustment to center the sidebands in
> the balanced modulator loop, and freely admit I am not an expert at this,
> but I dont twirl slugs or caps just to "see" what will happen, ha ha ha)
> So apparently, I have an aged component in LSB BFO circuit.
>
>
> Again, USB sounds great, good frequency response. LSB is clean, on
> frequency, but just narrow, maybe 2.1 kHz.....I have been using it, but I
> traded it to a buddy, (with full disclosure, of course), and he is happy
> with it. But I just wanted to make it perfect for the guy. he deserves it.
>
> My other thought was to put in a 2.8kHz filter...this might solve the
> problem, though in a back door way.
>
> Thanks to all for advice.
>
> K8VF
>
> ----- Original Message ----- From: "Ken Brown" <
> ken.d.brown@hawaiiantel.net>
> To: "Mark Kenward" <k8vf_mark@centurytel.net>; "Discussion of Ten-Tec
> Equipment" <tentec@contesting.com>
> Sent: Sunday, April 06, 2014 12:13 AM
> Subject: Re: [TenTec] Paragon II LSB/USB audio differences.
>
>
>
> The LSB or USB transmit signal is produced in the balanced modulator, and
>> then filtered to remove the unwanted sideband. The DSB signal that is
>> eventually run through the filter, to remove the unwanted sideband is
>> generated by combining the voice audio with the BFO. The signal produced by
>> the balanced modulator is supposed to be a clean double sideband signal,
>> with very little carrier. The carrier balance adjustment nulls the carrier,
>> and any residual carrier is further attenuated by the SSB filter. What is
>> left of that DSB signal after passing through the 2.4 kHz filter is
>> dependent on the BFO frequency and the shape of the filter. If it sounds
>> real good using one sideband, and not good using the other, they are really
>> only two possible causes either 1) the BFO frequency is wrong or 2) the
>> filter has poor symmetry. (This assumes there is not something else
>> changing, that should not change, when you change sidebands, such as some
>> control signal which should be identical for both sidebands, but somehow
>> changes. For instance, the balanced modulator gets unbalanced to produce
>> CW. It the logic that controls that is messed up, and unbalancing the
>> modulator in one SSB mode, that could be a problem. A leaky diode or bad
>> gate in the control logic might do that.) The only things that should
>> change between operation on LSB versus USB is the BFO frequency, and some
>> correction to the frequency readout, or shift of some other oscillator to
>> make the frequency display correct. There should be no change in the audio
>> level or frequency response feeding the balanced modulator, and no change
>> in the way the balanced modulator works.
>>
>> Most SSB filters are not perfectly symmetrical, and there will be some
>> minor difference in the sound of your transmitted signal when switching
>> sidebands. The difference should be something you really have to listen
>> carefully to notice. It should not be such a big difference that it sounds
>> "bad" on one sideband and "great" on the other.
>>
>> How have you confirmed the BFO frequencies are correct?
>>
>> DE N6KB
>>
>>
>>
>>
>> On 4/5/2014 4:34 PM, Mark Kenward wrote:
>>
>>> i have set Reference oscillator , and the BFO's on the rig.
>>>
>>> Rig is on frequency as discussed a week or so ago.
>>>
>>> My issue is this.
>>>
>>> USB sounds great on transmit.
>>>
>>> LSB, however, is thin. Narrow, like you are talking through a 1.8-2.1
>>> kHz filter.
>>>
>>> I tried another 2.4 filter in 9mHz slot, with no change.
>>>
>>> Can someone tell me what to adjust to move the USB and LSB transmits
>>> more to the center of their respective ranges.
>>>
>>> I am happy with the rig so far, but it is obvious that LSB needs an
>>> adjustment, and of course, it is not the BFO.
>>>
>>> I have a friend who wants the rig, and I would like to make it perfect
>>> for him.
>>>
>>>
>>> Thanks for any help.
>>>
>>> Mark
>>> K8VF
>>> _______________________________________________
>>> TenTec mailing list
>>> TenTec@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/tentec
>>>
>>
>>
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