[Drake] Re TR7 Main tuning knob

[Garey Barrell]

Rick -

You might try Charlie, K3ICH for the knob "brights". <pincon at erols.com>  
He has brights for Drake 4 and Collins, and may have something for the 
7.  He also has knobs and other 7 parts from time-to-time.

You don't need a big (noisy) fan on the back, just a gentle flow of air  
_blowing OUT_.

The power supply problem you are seeing, assuming your supply is well 
regulated, is drop along the cable.  The Drake supply uses four wires, 
two to run just the PA stages, and another pair to run the rest of the 
radio, (including the panel lamps).  Another approach, if your supply 
supports it, is a "four-wire" connection, with two small "sense" wires 
in parallel with the main wires to regulate the supply AT the radio.   A 
check of a wire table will tell you what the resistance of different 
wire sizes is, and Ohm's Opinion will tell you how much voltage will be 
dropped vs wire length.

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 4-B, C-Line&  TR-4/C Service Supplement CDs
<www.k4oah.com>


Rick Gouge wrote:
> Thanks everybody for your advice&  info. It seems that the Volume not going completely off on a TR7 is a Norm. Advice. Use the RF gain and AF gain together to bring the Audio down lower. I did and it works great. Now i need to replace the corroded disc on the knobs. E place i guess unless someone on here has spare parts?The previous owner put a dc i think 12 volt muffin fan on the back of the radio for cooling. I am thinking on finding a 110 ac volt Muffin fan and just plug it in the back where the stock fan would plug in. Makes more sense to me then having to worry about a wallwart powersupply for the DC fan, you think? Its a nice rig but it sure sucks the power  out of your powersupply. I found out pretty quick that i needed atleast a 35 amp powersupply and the Lights still dim on the TR7 when i transmit. Is this normal? It acts like it needs more amps to me. My power cable length might have something to do with it as well. It did seem pretty long,I think maybe 5 or more fe
>   et. Long cables are nice but they do draw amps if there not heavy enough wire for the length. I used a lot of power tools outdoors so kinda goes hand in hand i would think. 73`s Rick VE7RiK
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