[Hallicrafters] Dummy antenna for S40 alignment

Sat Dec 11 09:04:53 EST 2004

Does all this REALLY matter?  So what if there's a few db lost in Rx antenna
matching.  You're not gonna use your S-53A for meteor shower work on six
meters anyway.  Same for serious DXing or (heaven forbid) contesting.
  Even -10 db is only a couple S units.  If you are an SWL and your
boatanchor radio is your only ears to the world, then fine,  use a tuner.  I
doubt if any of us depend on vintage equipment these days for "serious" weak
signal work, so I just don't see all this receive antenna matching as being
worth the trouble.    However, I do agree with the concept for initial
alignment purposes.

On a related subject, it reminds me of the guys who put a digital readout on
their KWM-2, or a DSP filter on their SX-99.  To me, it defeats the purpose
of enjoying the older radios.  Part of the fun of using that equipment is
living with their eccentricities and limitations.   As an example, I enjoy
tuning around with an antique regen set.  It would totally destroy that
nostalgia to use some new-fangled solid-state device to enhance it's
reception.

73' Charlie k3ICH

----- Original Message ----- 
From: "George" <Thermionic_Emission at earthlink.net>
To: "Bill Gerhold" <k2wh at optonline.net>; "hallicrafters-mailman.qth.net"
<hallicrafters at mailman.qth.net>
Sent: Saturday, 11 December 2004 5:46 AM
Subject: RE: [Hallicrafters] Dummy antenna for S40 alignment

> Hi Bill,
> That's a good assessment, but if you dont have the proper balance between
> the tx and rx alignment, your up the creek. I only have one antenna and
> tuner. For your way to perform its magic you would need two antennas, or
be
> strictly an SWL. It would be most noticeable tuning up a transceiver, but
> no different with separate sets. The exception would be the
> combination  has an rx antenna trimmer to compensate. Without the correct
z
> at the antenna/radiator on both, you would have to re-tune the tuner at
> each tx/rx changeover. The reciprocity would get lost in the mismatch
> between the two. I only mention this having learned it the hard way.
Theres
> no free lunch.
> Good luck, George KB2Z
>
>
> At 09:26 PM 12/10/04 -0500, you wrote:
>
> >Exactly right, and that is why in all my station setups, I have used 450
ohm
> >balanced line and a tuner.  This is the only way I know, that my receiver
is
> >seeing the impedance it wants to see and I am getting maximum signal
> >transfer.  How do I know this?  Because the transmitter is tuned to the
same
> >frequency which is typically at or equal to 1:1 via the tuner.
Therefore, I
> >also have a low SWR for the receiver as well.
> >
> >I tried this little experiment, I pulled my SX-111 off line and connected
> >the rear antenna connector to my MFJ-259B with a short piece of coax.  I
> >then fed the MFJ signal into the receiver right in the middle of the 40
> >meter band.  Using the front panel trimmer on the SX-111, I was able to
get
> >a nice 1:1 SWR between the MFJ unit and the receiver.  Turning the main
> >tuning knob on the receiver from band edge to band edge, saw the SWR
slowly
> >creep up to way over 10:1 at the band edges with attendant signal loss.
> >
> >Hence, a good SWR is as important for your receiver as it is for your
> >transmitter.
> >
> >K2WH
> >
> >-----Original Message-----
> >From: hallicrafters-bounces at mailman.qth.net
> >[mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of Al Parker
> >Sent: Friday, December 10, 2004 8:52 PM
> >To: Craig Roberts; Edward B Richards; hallicrafters
> >Subject: Re: [Hallicrafters] Dummy antenna for S40 alignment
> >
> >hi guys,
> >     The main thing you wanta do is set up the rcvr for what impedance
you
> >plan to feed into it.  If the S-40 has no antenna trimmer, then you can't
> >do any adjusting other than your alignment, e.g. SP-600.  If it does
> >you've got some leeway. (don't stop hr)
> >     A resonant antenna is resonant on only a very narrow band of freqs.,
> >whether it has a balanced, open wire feedline, or what. So, elsewhere,
the
> >impedance is gonna be off, sometimes way off.
> >     What you really wanta do is use an antenna tuner for your receiver
if
> >you're "band cruising" no matter what antenna you use.  You've either
> >gotta tune the antenna system to the rcvr or the rcvr to the ant. sys.
> >     I've done it, and demonstrated it to others, with SP-600's.  Any
wire
> >is gonna be a very high, or very low impedance in many places across the
> >SW bands.  You can hear something then, but if you use a tuner and adjust
> >it to feed the rcvr in the imp. range it expects, just like "we know" we
> >hafta do with a transmitter, you'll hr more.  tuner - that's how you get
> >the best transfer of energy, rcvg or xmtg.
> >     that's my story & I'm stickin to it.
> >73,
> >Al the grouch
> >W8UT
> >
> >----- Original Message -----
> >From: "Craig Roberts" <crgrbrts at verizon.net>
> >To: "Edward B Richards" <zuu6k at juno.com>; "hallicrafters"
> ><hallicrafters at mailman.qth.net>
> >Sent: Friday, December 10, 2004 5:19 PM
> >Subject: Re: [Hallicrafters] Dummy antenna for S40 alignment
> >
> > >
> > > I was actually toying with the idea of building an old style open
feeder
> > > line doublet, per Army instructions, for my Hammarlund SP-600 (which
has
> > > a 100 ohm input impedance) and seeing if it would make any discernable
> > > difference.  Does anyone feed their antique receiver with an antique
> > > resonant antenna?  If so, how's it work?
> > >
> > > 73,
> > >
> > > Craig
> > > W3CRR
> >
> >
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