[Collins] kwm-2 fan and outputs

[Dr. Gerald N. Johnson]

Thank you. Dave's page seems to cover the topic well except that one 
circuit detail bothers me. I see the voltage doubler supply marked as 
grounded on the negative side, picking off 6.3 volts AC from some 
filament string in the radio, but that full wave voltage doubler expects 
a non grounded source which is not the case for the KWM-2. Is that 
ground not really grounded in the modern power supply assembly?

I'll post a copy of your answer to the Collins Radio Association list 
where the inquiry began.

73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association.

On 10/10/2010 10:20 PM, K5GNA at aol.com wrote:
> Jerry,
> I have been off of Ebay for a little over a year and working on my
> house. Had some Hurricane Ike damage and a lot of bad galvanized water
> pipes -- so we have done a complete remodel. I should be back on Ebay
> next month.
> I made a bunch of fans assemblies for Dayton, but haven't been actively
> selling them. I have two types in stock.
> The KWM2 version fits on the final cage with 3 original screws and will
> plug into the NB socket for power. It is $48.95 plus $8.00 shipping and
> handling for one and $2.00 shipping for each additional unit. There is
> no NB plug on the 32S.
> The 32S / KWM2 version fits on the final cage with 3 original screws, as
> above, and solders onto the back of the pilot lamp assembly for power.
> It is very easy to fit on the 32S since the socket is very accessible,
> so it takes just a minute or so to tack it on. On some KWM2's a bracket
> blocks the back of the lamp socket and you must first take the bracket
> off. It is $39.95 plus $8.00 shipping and handling for one and $2.00
> shipping for each additional unit.
> The original design for the brackets came from Dave about 16 years ago
> and I bought the rest of his stock of brackets a few years back and
> modified the bracket and built a small PCB to give either full speed or
> half speed with a switch (no off) . Half speed is pretty much silent and
> full speed is hard to hear at arms length.
> The NB mounts in the same space as the fan, but on the lid, so it is one
> or the other inside. The cable on the NB is long enough to put the NB
> out the rear of the radio if you really want to use it. Some of the
> Waters accessories like the Q Multiplier stick up into the left fan, but
> if it has a NB, then the NB would also interfere with the Waters.
> The bracket I was talking about on the solder in version mounts on the
> plastic nuts on the back of the meter, so it is not that hard to remove
> and saves you a few dollars if you want to solder it in. I just solder
> it into the unused holes on the lamp socket, so there is no trace of it
> if you want to remove it and keep it unmodified.
> Here is a copy of Dave's original article in Electric Radio in 1996.
> http://members.cox.net/daveishmael/KWM2FanBracket.htm
> I accept PayPal at this Email address and I am good at QRZ.com.
> 73,
> Bob,
> K5GNA
>
> In a message dated 10/10/2010 9:25:24 P.M. Central Daylight Time,
> geraldj at weather.net writes:
>
>     Google shows several hits referring to epay sales by K5GNA and he has
>     2674 comments, but nothing offered at the moment. Might be a direct
>     request would be in order. I'll carbon copy him with this for a
>     reaction.
>
>     73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association
>
>     On 10/10/2010 9:06 PM, Ron Manfredi wrote:
>      > The Collins web site:
>      > http://www.collinsradio.org/default.aspx
>      >
>      >
>      > on the Dayton Prize Donors page mentions:
>      >
>      >
>      > *KWM-2A Cooling Fan Kit*
>      > Bob Seydler, K5GNA K5GNA at aol.com, booth spaces 1310, 1313
>      >
>      >
>      > Could this be what your are looking for?
>      >
>      > 73,
>      > Ron
>      > WA2EIO
>      >