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SolderSmoke Daily News

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W1VD's Boatanchor Receiver Tests

Posted: 18 May 2022 06:15 AM PDT http://soldersmoke.blogspot.com/2022/05/w1vds-boatanchor-receiver-tests.html


I've been trying to get more rigorous in my evaluation of receiver
performance. My HQ-100 is tuned to Radio Marti, and it sounds great. But
how great is it really? And what about all the receivers and transceivers
I have built? How good are they?
Our friend Dean KK4DAS is about to start the rehabilitation of his dad's
old HQ-170A. A search for that receiver led me to Jay Rusgrove's very interesting measurement and analysis of old tube type radios. Jay's
results appear in the links below. More important is his very clear description of how the tests were done and what the results mean (link
below). Also included is one link showing a discussion of Jay's work.
Jay notes:
The decision of which boat anchor receiver(s) to own is seldom based on performance alone. A combination of favored manufacturer, period of manufacture, features, collectability or even just 'looks' often rank
higher on the priority list than receiver performance. Even if one were interested in performance specs much of the available information is
subjective as few receivers manufactured prior to the mid 70s have
undergone standardized testing. Hard data on minimum discernable signal
(MDS), blocking and two-tone IMD dynamic range is interesting to some
operators and important in an historical context as it shows the
progression of receiver development.
Jay designed the very first real transmitter that I homebrewed (The VXO 6 Watter from QRP Classics). Jay has been mentioned many times in the
SolderSmoke podcast and blog:
Jay's results: http://www.w1vd.com/BAreceivertest.html
Jay's methods: http://www.w1vd.com/Receivermeasurementbasics.html
Discussion: https://www.antiqueradios.com/forums/viewtopic.php?t=96872

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Troubleshooting and Fixing Old Faults in my Long-Suffering Hammarlund
HQ-100 (Part 2) (video)

Posted: 18 May 2022 07:30 AM PDT http://soldersmoke.blogspot.com/2022/05/troubleshooting-and-fixing-old-faults.html


Work continues on my old Hammarlund HQ-100. I give background on the rig
and explain the electrical trauma it likely suffered. Following Dave
K8WPE's dictum that we can still learn a lot from old receivers, I dug into this one. I wanted to fix a long-standing S-Meter/AVC problem. This led
me to an interesting troubleshoot, with at least one "waste of time"
detour. Eventually I found the fault in one of the coils in the grid
circuit of the RF amplifier. The coils had been smoked years ago, perhaps
by a lightning strike. I came perilously close to permanently losing 10-30 MHz. But I figured out how to fix the smoked coil. So my S-Meter/AVC
problem was fixed. I really like listening to this thing. There is still a
lot of nice material on the SW bands. There are some very nice broadcasts
in Spanish. Please subscribe to my YouTube channel.
You can see where the coil burned. Wire remained intact, but the
insulation burned creating a Primary to Secondary connection.
I just very carefully lifted one of the coils way from the other,
eliminating the unwanted connection.
Here's my homebrew "RC Printed Network" Z2 module. This was unnecessary --
the original was good. I put the original back in.

Electric Radio magazine recently ran a two part series on the HQ-100. I
have ordered these issues of the magazine.

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