[1000mp] MPV Driving SB220

[Mike Schatzberg]

Hello Cecil:

All the systems are custom for the amplifier involved.  You can see some of
the conversions on my W2AJI webpage here:
http://home.earthlink.net/~cherokeehillfarm/id2.html

73 and Happy DXing,

Mike
W2AJI
----- Original Message ----- 
From: "Cecil Acuff" <chacuff at cableone.net>
To: "All about Yaesu 1000mp" <1000mp at mailman.qth.net>
Sent: Tuesday, October 24, 2006 2:03 PM
Subject: Re: [1000mp] MPV Driving SB220


> Mike I'd be interested (off list) in your QSK conversions.  I'm currently
> rebuilding a Clipperton L and might want to include that..
>
> Thanks & 73
>
> Cecil...
> ----- Original Message ----- 
> From: "Mike Schatzberg" <cherokeehillfarm at earthlink.net>
> To: "All about Yaesu 1000mp" <1000mp at mailman.qth.net>
> Sent: Tuesday, October 24, 2006 10:25 AM
> Subject: Re: [1000mp] MPV Driving SB220
>
>
> > Hello Jim:
> >
> > Heathkit part number 69-55, is a TPDT relay, with a 110 VDC coil.  It is
> > indeed driven by switched DC voltage from the simple half wave power
> > supply
> > circuit off of one of the transformer windings.
> >
> > Perhaps Heathkit produced more than one version of the switching, which
> > handles both antenna transfer duties and bias switching.
> >
> > I have changed many of these amps to QSK using vacuum and reed relays,
and
> > usually have several pulls in the junk box here.  They are all DC
relays.
> >
> > 73 and Happy DXing,
> >
> > Mike
> > W2AJI
> > ----- Original Message ----- 
> > From: "Jan Erik Holm" <sm2ekm at telia.com>
> > To: "All about Yaesu 1000mp" <1000mp at mailman.qth.net>
> > Sent: Tuesday, October 24, 2006 11:06 AM
> > Subject: Re: [1000mp] MPV Driving SB220
> >
> >
> >> I see, then I do know what it is.
> >>
> >> Well now, the SB-220 has a AC operated relay, need
> >> I say more?
> >>
> >> 73 Jim SM2EKM
> >> ------------------------------------------------------------
> >> Bill Gode, Sr. wrote:
> >> > Snubbing Diode (From Wikipedia):
> >> >
> >> > When the current flowing is dc, another often seen form of a snubber
is
> >> > a simple rectifier diode placed in a circuit in parallel with an
> >> > inductive load (such as a relay coil or electric motor). The diode is
> >> > installed in the direction that ordinarily does not allow it to
> >> > conduct.
> >> > When current to the inductive load is rapidly interrupted, a large
> >> > voltage spike would be produced in the reverse direction (as the
> >> > inductor attempts to keep current flowing in the circuit). This spike
> >> > is
> >> > known as an "inductive kick". Placing the snubber diode in inverse
> >> > parallel with the inductive load allows the current from the inductor
> >> > to
> >> > flow through the diode rather than through the switching element,
> >> > dissipating the energy stored in the inductive load in the series
> >> > resistance of the inductor and the (usually much smaller) resistance
of
> >> > the diode (over-voltage protection). One disadvantage of simple
> >> > rectifier diode used as a snubber is that because the diode allows
> >> > current to keep flowing, the relay may stay picked-up slightly
longer;
> >> > some circuit designs must account for this delay in the dropping-out
of
> >> > the relay.
> >> >
> >> > 73,
> >> >
> >> > Bill, W9NHQ
> >> >
> >> >
> >> > ----- Original Message ----- From: "Jan Erik Holm" <sm2ekm at telia.com>
> >> > To: "All about Yaesu 1000mp" <1000mp at mailman.qth.net>
> >> > Sent: Tuesday, October 24, 2006 8:34 AM
> >> > Subject: Re: [1000mp] MPV Driving SB220
> >> >
> >> >
> >> >> What is a snubbing diode? I have never heard that
> >> >> expression before.
> >> >>
> >> >> /Jim SM2EKM
> >> >> ---------------------------
> >> >> Pete Smith wrote:
> >> >>> You can also play safe by putting a 220-ohm resistor in series with
> >> >>> the switching lead to limit the current through the relay contacts;
> >> >>> that device was published in QST many years ago, when relays in
> >> >>> TS-930s like mine were being fried by the relay current - the stock
> >> >>> SB-220 relay has no snubbing diode, which may be part or all of the
> >> >>> problem.
> >> >>>
> >> >>> 73, Pete
> >> >
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> >> >
> >>
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