[Elecraft] loss of RX sensitivity

[Gwen Patton]

Reminds me of having to blow on the contacts in a Nintendo game cartridge
to make it work in the console. ;)

On Mon, Sep 17, 2018 at 7:31 AM rich hurd WC3T <rich at wc3t.us> wrote:

> I guess that’s the electronic equivalent of blowing through a tube to clear
> the blockage.  :)
>
> On Mon, Sep 17, 2018 at 01:44 Frederick Dwight <kl7cw at mtaonline.net>
> wrote:
>
> > Scott,
> >      The problem you describe is actually quite common in electronics.
> In
> > the telephone industry, especially in the “good old days” with wire
> cables,
> > sometimes with many splices it was common to get drop outs.  These could
> be
> > due to a splice, wire wrap connection, oxidized relay contact or
> whatever,
> > especially with only low level signals.  If the circuit also had a DC
> > voltage on it, the problem often did not exist.  In fact it was common on
> > critical circuits for the FAA or military, or whatever to sometimes just
> > put “sealing current” on certain circuits just to be sure it was
> reliable.
> > Often we used 24 volts DC or less with only a few ma of current.  At one
> > time I had many phased verticals which were controlled by many relays.
> > Occasionally the received signal would drop by many S units.  Sending a
> > single dot, even with QRP or QRPP power always cleared the problem,
> > sometimes for weeks or months.  So it could be a connection in the
> antenna
> > system, a plug on a circuit board, or even a relay.  I have never
> > experienced trouble with Elecraft relays personally.  Sometimes PL-259
> > center pins are not correctly soldered, and can present similar symptoms.
> > You could try a random wire, or even something like an 80 meter dipole on
> > 30 meters, just to see if it was anywhere in the antenna system.  Even a
> > volt or two is often enough to punch through a poor solder or oxidized
> > connection, but even something like a 0 dBm signal is just not enough.  I
> > have identified problems with BNC connectors and adaptors purchased at
> ham
> > flea markets which are just not reliable and are probably factory
> rejects.
> > So look into your antenna system before you dig into your rig.  You could
> > also hook a signal generator to the rig and see if it receives OK on all
> > bands with something like less than an S9 signal.  Be sure to not
> transmit
> > into your generator, and/or set your tx to very low power.  Good Luck
> >  Rick  KL7CW
> >
> > Sent from Mail for Windows 10
> >
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> --
> 72,
> Rich Hurd / WC3T / DMR: 3142737
> Northampton County RACES, EPA-ARRL Public Information Officer for Scouting
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