[GreenKeys] Dovetron unit

[wa2hwj@att.net]

Larry,

If you suspect heat, try running the unit without the
top cover. There's nothing inside the unit that would
create RFI. You might also check to see if your unit
has calibration pots inside for the mark/space tuning
controls. Those pots are single-tune types and they
might be a little "dirty". 
Does your unit have the low frequency
mod (goes down to 300 HZ on the tuning knobs)? That
modification adds some additonal circuitry to the
m/s tuning system. 
By the way, if you have the internal HV loop, there is
definitley heat inside the box from the current limiting
resistors. 
My workhorse Dovetron, which is the loaded "ham version",
does get warm and I have noticed similar start-up drift.
But I've never worried about it too much. Remember, all
of the chips are the plastic types and they're at 
least 20-25 years old! And, some of the Dovetron's
circuitry leaves a lot to be desired as far as
voltage regulation. 

73,
Jack WA2HWJ

> I've been running my Dovetron MPC-1000C now for 2 days to watch the display.  
> It appears that after its warmed up the space tuning seems to drift off 
> abit.  Receiver is an FT-990 that is very stable so i know its not whats 
> moving.  Even if it were, the Mark and Space tuning would then both need 
> readjusting and that's not whats happening.  It is a persistant situation.  
> Do any of you other owners experience the same thing?  
> 
> I think for RFI prevention the top cover needs to remain in place but some 
> ventilation or air movement inside would help this thing out.  I've opened 
> the lid and performance seems to improve.  Sure hate to drill holes to make 
> air move.
> 
> This appears to be an earlier version and the manual i have which is for the 
> MCP-1000CR/T is only relative.  Lots of things they talk about in the manual 
> are not on this unit.
> 
> Larry
> W0OGH
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