Home About K9EW Radios For Sale Links
Argonaut 515 PTO Rebuild
Need to get to that PTO in your Argonaut 515? Be prepared to remove the
Front Panel, and a couple of PC Boards. Here's how I did it...
Argosy 525 PTO Rebuild
All TenTec PTO's need to be cleaned and re-lubricated occasionally, and that
job is the same from one TenTec rig to the next. But getting the PTO out
of the radio is the interesting part, and it's not always obvious how to do it
with minimum disruption to the rest of the radio. Here's how I got to the PTO in my Argosy 525...
Argonaut 509 IF Crystal Filter
The venerable Argonaut 509 is a great little rig, but something had to be
done to the IF bandwidth to make it a respectable CW receiver.
TenTec PTO Tuning Knob Sensitivity to Hand-Capacitance
TenTec made a lot of great rigs using the PTO design, but they all seem to be
sensitive to having your hand touching or even being close to the metal insert
or the metal skirt. This is what I did to cure that problem once and for all.
Half-Size Inverted Vee
I didn't have room for a full-size dipole on 40m, so I started with the space I
had and worked backward.
Extending
the Life of a Collins 75S- Receiver
Don Kang wrote an article for the Collins Radio Association? about reducing the amount of heat
generated in a 75S-1 or 75S-3 receiver. Reducing the heat build-up will
extend the life of these classic rigs.
Collins 32S/75S QSK PDF Document
Gayle Lawson, K0FLY, designed a QSK circuit for use with the Collins S-Line. From time
to time, the question of QSK operation comes up on the Collins reflectors, and
I'll make reference to Gayle's article, which is in the CCA archives. Invariably, I get several requests for the article, so I'm making it available to save me some time.
Boat Anchor QSK
I've searched for articles about QSK for the old tube-type rigs from the era
when I was getting started in ham radio. There are three components to this
project: the Keyer, the Antenna Switch, and the Control Circuit for the Rx
and Tx. I've taken bits and pieces of different ideas that I've found, and
combined them into something pretty simple to build. No frills, just
function. The Control Circuit has not been completed yet, so only the
Keyer and the Antenna Switch are shown. Both have been tested, and work
quite well.
Homebrew PAC-12 Antenna
I've had surprisingly good results with this very portable, shortened vertical
on 20m.
20m Twinlead Inverted Vee
This antenna is simplicity personified, but there are no compromises, and its
performance is first-rate.
TenTec Knob Repair
TenTec makes great rigs, but some of their knobs crack inside if you
overtighten the set screw, or sometimes just with use. Here's how to
repair the broken ones and prevent the new ones from breaking.
A BCI Filter for your Antenna Analyzer
I was thrilled with my new MFJ-259B Antenna Analyzer, but the 50kw AM broadcast station a mile away made it impossible to use my new toy. Here's the filter I used to suck out the
broadcast signal and make my Antenna Analyzer usable.
K2 AF Gain Mod
I didn't build my K2, so when I wanted to install the AF Gain Modification, I didn't even know which screws hold the top cover on. I thought that some additional documentation for others like me might be useful.
Paddles, Keyers, and Keys
I don't remember how I got started building my own keys and paddles, but it may have had something to do with QRP operation. As my rigs got smaller and lighter, my Bencher paddle probably seemed out of place.
How to Ship a Boatanchor
As an occasional shipper and receiver of boatanchor rigs, I've learned a lot about the proper way to pack a radio. Here's a method for packing a radio that has worked for me many times. I wish all the radios I've received had been packed using this method, because some of them are now "project" radios.