On Tue, 2 Mar 1999 09:19:36 -0800 Rich Measures <measures@vc.net> writes:
>>
>>
>>
>>On Wed, 24 Feb 1999 01:00:57 -0800 (PST) john merryman
>><andy_m_99@yahoo.com> writes:
>>>
>>>
>>>
>>>Am i missing something about the YC156.
>>
>>Yes you are....
>>
>>>It has 5k plate dissipation,
>>>its rated for pulse use.
>>
>>Not completely correct. The YC-156 is a selected version of the
>>3CPX5000A7. It is selected for high emission and excellent linearity
>for
>>medical use.
>>
>>
>>>What would be the realistic operating
>>>parameters in SSB, to stay within the plate dissipation of 5K. You
>>>end up with a tube that is similar to a 3cx3000 output wise, with a
>>>very poor 3rd order imd figure. The data sheet does not mention any
>>>high linearity figures, is this urban myth?
>>
>>Use the 3CX15000B7 for curves since the YC156 uses those internals.
>>
>>
>>>I think the 8171 in class A would be more linear and have a better
>IMD
>figure.
>>
>>Arguable. The YC-156 has so much extra reserve emission even when
>run at
>>the 5KW dissipation level.
>>Third order IMD in the > -45dB range are reported in ham SSB service.
>
>? Sounds reasonable. Which ham transceiver has <45db 3rd order IMD?
>>
>>
>>
>>>The 8171 would also have more grunt.
>>
>>For CBers and CB style hams.
>>
>? _______
>
>>>But i might be missing the point of this tube. Please explain why
>this tube
>would be
>>>favoured?
>>
>>Cheap, available, no socket required, reasonable filament
>requirements.
>>Can run legal limit RTTY at modest Ep. For a low investment it can
>be
>>the basis of an amp that will last darn near a lifetime.
>>
>? One of the flies in the ointment is that the substantial amount of
>C-out does not facilitate reduced anode-current operation on 10m.
The ways around that have been covered several times.
.
>In
>other words, in other words one needs several hundred watts of drive
>to
>make it come alive.
Wrong!
. Another fly is the lengthy preheat time
Subjective and depends upon individual needs. Only twice as long as the
8877.
73 Carl KM1H
>
>- cheers, Carl.
>
>
>Rich...
>
>R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
>
>
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