[BC] Power efficiency vs transmission quality

[Robert Meuser]

Milton R. Holladay Jr. wrote:

>Adjusting the audio driver balance in a Gates BC-1T w/plate on, or the
>driver loading in a BTF-3E  is far more dangerous than adjusting the 316;
>you'd have to be very careless to get shocked.
>
Except I saw someone get dead inside the 316B

>I got the distinct impression that the B was a drawing board to physical
>  
>
>reality type thing, as there were few updates, mods, or follow-up notes.
>AFAIK, there were only ~15 made.
>
>In the early 70s, a fellow upstate was building a 50kw site. He went to WBT
>to see their MW-50 and to Fayetteville to see their 317C, commenting that it
>was like comparing a Chevrolet to an army tank. AFAIK, he's still running
>his 317C.
>  
>
That is a tough call.  The 317 C series is definitely the heavier metal 
but you really need to know how to tune it. The MW 50, depending on the 
version uses less power and is equal to the 317C performance wise. I 
spent a lot of time (too much time) comparing specs after the fact 
including maximum positive modulation, distortion, stereo separation, 
IPM, stereo distortion and the two TXs can come up the same except the 
MW 50 consumes less power and depending on how you feed it can do more 
positive mod.


>And speaking of J. Fred, did he ever really say "A man is naked without $500
>in his pocket" ?
>M
>
>----- Original Message ----- 
>From: "Robert Meuser" <Robertm at broadcast.net>
>To: "Broadcasters' Mailing List" <broadcast at radiolists.net>
>Sent: Friday, February 23, 2007 10:53 AM
>Subject: Re: [BC] Power efficiency vs transmission quality
>
>
>  
>
>>I have worked with J Fred, he even stayed at my house at one time and I
>>respect his accomplishments. However, the 317B was way before his time.
>>It is a linear amplifier driven by a 316B. There is no way in the world
>>a 316B comes close in the modulation category to a 317C series. Trust me
>>I ran both at the same time. This is not even a close call. The 316B was
>>also a power hog. It was three 4cx5000s screen modulated, no Doherty
>>technology.  The linear to make 50 KW was a Doherty but the combination
>>does not even run close to the 317 C package in either modulation or
>>efficiency.  It was also possibly the most deadly TX package ever built.
>>I would not agree that the 317 C-3 was as good as it got for a tube TX.
>>I would prefer the MW-50C series, which had the solid state mod driver.
>>I had 317 C 2s and worked very closely with Joe Sainton who did many
>>mods on them. We jokingly called them 317 2.5 as they got as close as
>>you could to a C-3 without extreme surgery. I bought an MW50 C series
>>for another station after doing a real world head to head comparison.
>>
>>R
>>
>>
>>Milton R. Holladay Jr. wrote:
>>
>>    
>>
>>>According to J. Fred, the B and C had about the same overall
>>>efficiency, but
>>>I've never looked it up to check....And modulation was no problem with
>>>good
>>>tubes. A mod to bypass the input xfmr would have made it free of audio
>>>iron.
>>> Of course, the 317C-3 was as good as it got in tube 50s.
>>>The main consideration about tube boxes is whether it was a GOOD xmtr,
>>>or a
>>>POS. Some of the 50 year old tube xmtrs were a lot better than the 30
>>>year
>>>old tube transmitters.
>>>M
>>>      
>>>
>
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>  
>