[TMC] TMC-SBT-1KB

[Roy Morgan]

On Jul 2, 2008, at 12:21 PM, Roy Morgan wrote:

>
> On Jul 2, 2008, at 2:21 AM, H.L. wrote:
>>
>> Pin J: +225VDC B4...
>> I think the power transformer HV is 350-0-350 VAC.
>
> Pardon me if my memory here is not quite right -

I did just look up the schematics.  They don't show the current needed  
for the B+, nor does the SBE-3 manual I just studied.  The B+ fuse,  
however, is 0.25 amp.  That would indicate to me a total B+ draw of  
some 100 ma or so.  The total power consumption with oven off is 120  
watts.  Output impedance is specified as 72 ohms, max output power one  
watt.  (Note, the GPT-750, rated at 750 watts PEP will usually deliver  
some 1300 watts CW steady state output at the RF jack, and do that  
24/7.)

I did find notes that the SBE transformer "HV" winding is 175-0-175  
ac. The rectifier is in fact a 5R4.  It's a choke input filter, so the  
AC needed at the rectifier plates would be higher than with a  
capacitor input for the same B+ level.

Roy

Roy Morgan
k1lky at earthlink.net
Lovettsville, VA 20180