[Drake] TR-7 current from 13.8 VDC supply

[GGLL]

	Ok, thank you guys for the answer; I was also not aware of the internal 
current trip, nor where is it located; is it a variable adjustment or a 
fix one?.

	I'm trying to fix a TR-7 here, the problem is....., low power output at 
10 Mtr. band. I obtain the expected 150 watts of power at 40, something 
less at 80, 130 at 20, maybe 120 at 15, but 28.5 MHz only offers 50 
watts, with a DC current of 25 A!!. Also, at 80 this current is nearly 30A.

	Based on Jack comments it looks fine, but I have less than 20 A of 
current for the same power out in let's say a TS440 rig. Make your 
calculations for efficiency!; so I figure something is wrong, although 
there is no smoke anywhere in the rig.

	This rig has the #2 version of predriver board, I've included the neg. 
feedback resistor at the MRF476 driver emitter (a bit less power out) 
and reinforced/added ground connections at final and predriver boards, 
and readjusted some of the pbt/2nd IF coils.

	It is like the finals are working into a mismatched circuit, I mean the 
surrounding components (transformer, SM capacitors, etc.).

	Maybe I have to take out the final board and check components one by 
one. Or chek it without LPF. The transistors are the original ones.
Well, any help is Greatly appreciated. Thanks.

Regards
Guillermo - LU8EYW.


jde1033 at sympatico.ca escribió:
> OM,
> 
>     My TR7 needs 25 amps @ 13 VDC for 100 watt output which seems to
> 
> be according to specifications.  Still a good rig but I am going to sell 
> mine
> 
> soon as I dont need it.
> 
> GL with the TR7 & best 73,
> 
> Jack.  VE3BHW
> 
>  
> 
> 
>  > How much DC current taken from a power supply can I expect when
>  >transmitting at full power, at the different bands, CW mode?.
>  >
>  >Regards
>  >Guillermo - LU8EYW.
>  >______________________________________________________________
>  
> 
> 
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