Subject: Time: 9:20 AM
OFFICE MEMO 38S Receiver Gotcha Date: 3/11/97
38 Special builders,
A recent post to the list mentioned the importance of paying close attention to the various polarized parts in the 38S. One that I got bit by has to do with T1. I was not hearing the two peaks on tuning TC1, despite removing one turn from the T1 secondary, and then removing a second turn. Audio output levels were low, and not too many stations. Turns out my problem was with the T1 *primary* winding.
The manual shows the correct way to wind and install T1. I inadvertently had the 2 turn *primary* installed backwards. This screws up the phasing of the transformer, and results in not getting the proper tuning with TC1. Once I fixed this, and hooked the 38S up to a resonant dipole, the results were amazing. Two nice distinct peaks with TC1. Sunday afternoon at about 2300Z, the band was loaded with signals, and I had to turn the RF gain down most of the time. This receiver definitely works!
BTW I have shorted out R24, changed C4 to 10 pF per Jim Kortge's post from a few days ago (and made the T1 secondary 17 turns), and am using 1K ohm *communications* headphones from RS. Of course, your mileage may vary, but if you suspect your receiver is not performing up to snuff, check out T1, and read the fine manual.
73
Mike WA6MER
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