[TMC] Sideband Exciters

[Meir Ben-Dror WF2U]

Chris, 

The SBE-2 generates the sidebands at 17 kHz, so it has an additional conversion up to 287 kHz, from which the final conversion is done to the desired output frequency.
The SBE-3 generates the sidebands at 250 kHz and the final output frequency is derived by a single conversion.
It is a bit inconvenient to switch from SSB to AM, and for good carrier vs. sidebands ratio you have to set both audio inputs to the same level and set that level to the carrier for the proper percentage of modulation. The best way to set and monitor this is with a scope via the modulated RF output sampling. 
That's why I also got a GPE-1A for AM (not in the rack), so I can leave the SBE-3 settings for SSB, switch the exciters' inputs and outputs to the MO and the linear. 

73, Meir WF2U
Landrum, SC
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On Aug 27, 2021, 3:13 PM, at 3:13 PM, Chris Bolkan <bolkyboats at gmail.com> wrote:
>That is an awesome build Meir! Very clever and neat looking
>implementation!
>
>My goal is also to ultimately build a complete basic TMC station. To
>that end I have GPR and PAL but no SBE or Master oscillator which is
>why I am trying to figure this out. I have to know what I am looking
>for so if/when it becomes available I know what I need :-)  By the
>way, thanks for the tip on the SBE models.
>
>Now I understand that the SBE will run self contained on crystals, but
>to variable tune it will require a VOX of some kind. I have not looked
>at the PMO's so will do that to become a bit familiar with them too.
>For my use I cannot imagine requiring multiple outputs that you say
>the 0-330 does, but it is a Nice looking piece!.
>
>I wish there was more information and examples on how this TMC
>equipment was actually deployed and used. It would be a godsend to
>understanding all of the individual components they produced. One
>thing is certain. They were prolific designers and created some
>beautiful equipment!
>
>Chris
>
>On Fri, Aug 27, 2021 at 11:18 AM Meir Ben-Dror WF2U <wf2u at ws19ops.com>
>wrote:
>>
>> Chris,
>>
>> Nick is correct of course, but as TMC master oscillators are
>concerned, besides the VOX series, you can also use a PMO if you need
>only one output. Another advice: the older SBE-2 is a pain in the neck,
>but the SBE-3 (and up) is much better and if needs to be, easier to
>align.
>> Here is my multi-mode 350 W TMC system I put together; I had enough
>space in the rack to mount the GPR-90RXD receiver in it as well, and a
>homebrew dual speaker panel, for single rack integrated station. I have
>a PMO in there, because the VOX I have needs some work, but I'll keep
>the PMO in the system.
>>
>> 73, Meir WF2U
>> Landrum, SC
>>
>> Get BlueMail for Android
>> On Aug 27, 2021, at 1:59 PM, Nick England <navy.radio at gmail.com>
>wrote:
>>>
>>> Yes you also need a variable master oscillator like the TMC VOX
>(O-330).
>>> Otherwise the SBE can run crystal-controlled and has a switch for
>multiple
>>> crystals. For many government and commercial applications, crystal
>control
>>> was fine.
>>> Hey, it’s TMC.
>>>
>>>
>>> On Fri, Aug 27, 2021 at 1:31 PM Chris Bolkan <bolkyboats at gmail.com>
>wrote:
>>>
>>>>  Hi TMC lovers!
>>>>
>>>>  I have been looking at a few TMC transmitters on the history site
>and
>>>>  am confused about something. It seems that most of the systems
>have a
>>>>  master oscillator (0-330 or something like that) in addition to
>the
>>>>  SBE exciter (SBE-3 or 3 or whatever)
>>>>  I am hoping to assemble a complete working transmitter at some
>point
>>>>  if it ever becomes possible to obtain the components, but at this
>time
>>>>  I know precious little about what is actually required to assemble
>a
>>>>  working transmitter. I thought based on reading and images of the
>>>>  controls on the SBE's that they contain the required oscillators
>and
>>>>  are self contained. My question is do they? Or is the 0-330 master
>>>>  oscillator required in addition to the SBE to have a fully
>functioning
>>>>  exciter, or is the "master" oscillator an "extra" that allows
>>>>  synchronization of multiple transmitters and receivers and so
>forth? I
>>>>  apologise if this is an ignorant question. I suppose I could
>>>>  eventually figure it out if I read enough on the history site, but
>>>>  it's not always easy to figure everything out looking at just
>manuals
>>>>  without an understanding of the original deployment and (intended
>use)
>>>>  for these devices.
>>>>
>>>>  Thanks in advance!
>>>>
>>>>  Best regards,
>>>>  Chris
>>>>  KI7NXY
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