One of my Y-BOX customers, AMSAT President Barry Baines, WD4ASW, reported a
problem when connecting the following devices in parallel to the ACC port
of his Elecraft K3:
1. KAT500 / KPA500
2. RemoteRig Interface
3. 4O3A Antenna Genius (in "BCD" mode)
Automatic band switching worked normally *until* he connected the Antenna
Genius, a 2x8 combination band decoder and antenna switch (see
http://www.4o3a.com/index.php/products/station-automation/antenna-genius/).
Once connected, the KPA500 got "stuck" on 60m. If he disconnected
everything *except* the Antenna Genius, it worked fine *until* the KAT500 /
KPA500 was reconnected.
Long story short, the Antenna Genius band decoder was drawing down each K3
band data line from +5V to +3V as soon as it was connected. In other
words, this device, in BCD mode, cannot coexist with any other device that
also uses the Band Data lines, such as a KPA500 or a Top Ten band decoder.
Even a KPA500 in AUXBUS mode (Radio=K3), it still requires proper voltages
on the band data lines to switch automatically.
Switching the Antenna Genius to "Pin to Port" mode, and driving it with 12V
signals from an external band decoder such as the Elecraft KRC2 or a Top
Ten Devices Band Aide would have solved the problem, but Barry already had
a band decoder built into his Antenna Genius antenna switch, and didn't
want the expense of adding a yet another external device, or wiring up new
cables. Switching everything via software was also rejected.
To address this, I designed and built a prototype "Band Data Isolator" to
isolate the Antenna Genius's band data pins from any other devices
connected in parallel. Barry reports that it solved the problem.
The isolator circuit requires about 12V, but uses very little current, so
it can easily be powered from the K3's 12V DC output or a 13.8V station
power supply.
I am thinking of designing a new version of the Y-BOX to solve just such a
use case. It would be a 1x4 accessory port splitter just like the original
Y-BOX, but with one of the ports dedicated solely for the band data pins of
the Antenna Genius. One of the RCA connectors would also be dedicated as a
+12V DC input.
If you think you might want one of these, please let me know (off list).
The more interest I see, the more likely it is that I will design this new
"Antenna Genius" version of the Y-BOX. It could also work for any other
devices that cause similar problems when connected, though no other Y-BOX
customer has reported a problem to me yet.
Thanks to WD4ASW for helping me to debug and to resolve this interesting
situation. Thanks also to 4O3A, 4O9ITT, W6FB and W2SC for advice and
consulting.
73,
Bob, N6TV
[hidden email]
https://bit.ly/Y-BOX______________________________________________________________
Elecraft mailing list
Home:
http://mailman.qth.net/mailman/listinfo/elecraftHelp:
http://mailman.qth.net/mmfaq.htmPost: mailto:
[hidden email]
This list hosted by:
http://www.qsl.netPlease help support this email list:
http://www.qsl.net/donate.htmlMessage delivered to
[hidden email]
Locked
