Curious about the I.R.E. Standard Dummy Antenna
This link seems to be broken.
Pete, I remove temporary items from my web site pretty quickly due to
space restrictions. I tried to e-mail the chart to you but got the
following reply:
----- The following addresses had permanent fatal errors -----
(reason: 591 your host [216.86.143.7] is blacklisted by
bl.spamcop.net. No mail will be accepted)
No more midnight spam for me! Anyway, the chart is back up for a couple
more days.
By the way, on the perfboard I used to build my dummy antenna I added a
0.1 uF coupling capacitor between the signal generator input and a
second output lead with an alligator clip. This provides a 50-ohm
DC-isolated signal for IF alignment. I usually align radio IFs by
sweeping a signal at the front end, often just blasting through the RF
and mixer stages at 455 kHz. But the alligator clip is handy when I
want to drive the mixer grid directly. You can drive the grid with the
dummy network, but the 50-ohm source impedance of the direct output
ensures that the parallel impedance at the grid doesn't affect the
sweep flatness.
Brian
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