|Ive been getting many requests by email for Ten Tec
Argonaut parts lately and in fact over the last 10 years or
so since I put up this web site:
www.hamelectronicsmagazine.com and my newer more
commercially inclined web site:
I have tried to gather old rigs and parts for old radios
and to some degree I have been sucessful but the most
commonly requested parts for the older Argonaut radios
are quite hard to get. Knobs, front panels, side panels,
dial cords the 5 pin (special) accessory plug for the
audio filter that plugs into the back -- these are all
custom parts that Ten Tec manufactured using their
plastic injection molds.
Ten Tec is still on the web but they have little or no parts
advertised for these older radios. Up until about a
couple of years ago, Ten Tec did have PTO rebuild kits
and certain other parts available for the 505, 509 and 515
but now -- I dont know if they even sell PTO kits.
Fortunately - a few years ago- I bought 3 PTO rebuild kits
for my own use.
Ten Tec Argonaut 505/509/515 tips and questions I have
answered about parts and parts availability for these old
sentimental favourites. Knobs, dial strings, cursors,
cabinet parts and sometimes discrete electronics
components are often highly sought after
|Potpourri of Ten Tec Argonaut 505/509/515 questions and tips -- new article August 20/2016
|Written by Earl Andrews VE3AB (Ham Electronics Magazine (.com) and Netty Electronics
|Above-- a nice little collection of Ten Tec radios that a ham in Hawaii sent me a picture of.
He was looking for a pair of side panels for a 509 he had acquired and I managed to find
him a pair that were a bit blistered on the sides but certainly useable.
My two web sites have helped me contact and correspond with many hams who still like the
old equpment and they work at fixing and restoring it as well. For some it is a hobby within a
|Above is the Model 208 AF filter that goes with either the 505 or the 509. Note
that the 515 Argonaut changed to a different type of connector. This connector
in the picture is highly sought after for use with the older Argonauts and I get
people writing me for this one. I wish I had a hundred of them! I might have
one or two spares in my collection and I am holding onto them.
|ANOTHER GOOD PAGE of useful tips for Argonaut repair
and restoration that I wrote some time back can be found
at this link:
|Upside down dual gate mosfet in a home made socket. The socket material is made from the pins of these 40 pin Single in Line
machined 40 Pin DIP SIP IC Sockets Adaptor Solder Type that can be bought on line. I sell them here for about 75 cents each.
The Argonaut RF amplifer Dual Gate mosfet is easier to reach and solder from the solder side of the board ..so I mounted this
transistor upside down to get the PIN OUT -- CERTAINLY not A REAL GOOD METHOD..BUT IT WORKS!!!! The Dual Gate in the Front
end receiver of the Argonaut sometimes goes bad. Could be because of power supply spikes, capacitors not filtering properly or a
spike on the antenna receive circuit caused by static electricity or rain static or thunderstorms. Also perhaps a transient from
keying the transmitter part of the circuit. There are protective diodes which are there to protect the sensitive DG mosfet.
SEE THE SCHEMATIC/BLOCK DIAGRAM BELOW RIGHT --->>
|This article is under construction....9 OCTOBER 2016 and wont be finished for a week or two or
maybe even a month or two!!! --- So check into my site from time to time and you might find
some new interesting articles or articles I finish off. Im a retired Civil Servant here in Canada and
writing articles and selling components and fixing gear gives me lots of enjoyment and keeps the
mind fertile and alive.
73 earl ve3ab
|The ham in Hawaii wrote me back the other day and he now has a Ten Tec 405 Amplifier.
This is a great little companion to the older Argonauts or any low power transmitter in fact.
Sometimes you do need a little bit more power to make a QSO work. NOTE: A good guideline
is to use the minimum power needed to carry on a qso.
|The Argonaut uses two diodes back to back. I prefer the 4 diode method.
Two in one direction and two in the other. This is because large signals
like powerful broadcast band or short wave transmitters can forward bias
the basic protective circuit consisting of only 2 diodes and cause
spurious emissions in the receiver and distortion ect.
|Earl, I think I really found the problem this time on the IF board of my 509. I dont have the exact numbers at the moment, but its the capacitor between Q2
mosfet and the tunable coil. The 509 was working great since I changed the electrolytics on that board. Today I turned on the 509 and it was dong that 40dB
deaf thing again. I started wiggling components and this time when I wiggled that one capacitor the receive sensitivity jumped up enormously. So tomorrow
I'll pull out the IF board and either find a cold solder connection or that capacitor is bad. One lead on that capacitor seems a bit iffy. . Anyway big sigh of relief
on the IF board problem and good thing I didnt throw away all the other mosfets that were in there. They are probably all good. Ok thanks for listening! More
later. 73 Aloha Gar(iDENTITY PROTECTED)
|Below a note (email) I received from this fellow in Hawaii
who has the Argonaut/Ten Tec collection seen in the
photo above. He has been corresponding with me
concerning his repairs of an Argonaut 509 and I will pass
some of them on to you "radio repair guys" and tinkerers.
Also those who like to think about repairs and technical
|So l plug a mic into the 509 and very little output. Earlier I
did know something wasnt right because putting the rig
into lock gave little output unless the carrier balance trim
pot was at either end of its rotation. A good board read
about 4.75 volts on all 3 terminals of the c b pot. The bad
board about 1 volt. I then measured the value of the pot. It
was open. Supposed to be 10k. Replaced the trim pot and
that fixed the problem.
So there you have it. -- a simple repair once you find the
defective component. This fellow from Hawaii is a pretty
good tech actually. He works as a radio repair person.
But..you dont have to be a pro to fix these older rigs. The
older argonauts have in their manuals voltage charts and
you can do some basic DC measurements and often come
up with a solution. --- IF YOU NEED PARTS HERE IS
WHERE I COME IN. I do small orders and I can match up
parts for you. I have my own Argonaut collection of 505,
509 and 515.
|ANOTHER NOTE FROM THE HAWAII HAM BELOW;
|COMPONENT TESTING. -- Here are some of the component testers I have. I bought them from Ebay from China and Hong Kong. The Chinese do have some
real nifty stuff. They also sell some real bad discrete components for some crazy reason!!???!!! - I do like these Chinese testers. I cannot do without them
now. -- Just like the fellow from Hawaii said in the notes above: good thing I didnt throw away all the other mosfets that were in there. They are probably all
good.-- A tester or two ..or three -- is almost indispensable when working with small discrete components.
IMPORTANT NOTE: for measuring purposes I use some GOLD STANDARD BENCHMARK components just to make sure these inexpensive testers are
giving me good readings. Every once and awhile..they seem to be giving out some erroneous data. So I always go to my Gold standard bench mark
components to ensure the tester isnt giving out some sort of bogus data with a software glitch or something. -- Most of the time these testers work
great but I like keeping them honest. -- This is especially true with LC testers and small capacitance or inductance measurements.
Sometimes you need to CALIBRATE THEM or even turn them on and off and reset them. Not often ..just every so often.
NOT SHOWN in the above photo graphs is my LC tester. It is from China/ebay as well. It measures down to 1 uh inductance and small capacitance values
which the above 3 testers cannot deal with. The LC tester runs about $30 as well. It is especially tailored to Inductance and Capacitance measurment and it
is almost indispensable for my bench work.
With the LC tester I keep my CALIBRATION COMPONENTS (my KNOWN VALUES of inductance and capacitance) which are in the range of the components I
am working with at the time. -- For HF coils that are in the 1 to 10 uh range I keep my 1uh coil close at hand.
|Wiggling and probing and putting gentle pressure on components can be a
valuable method of trouble shooting. Sometimes cold solder joints can be found
that way. -- See the PHOTO RIGHT of the bad epoxy capacitors I found in one
Argonaut 509. -- The entire article concerning these bad capacitors and the
consequences they had on the radio is found in this other article I wrote:
http://www.hamelectronicsmagazine.com/argtlopwr.html -- Be sure to take a
close look around as you are poking and prodding and wiggling. You may spot
|When I removed the cracked capacitor the lead
just fell off.
Its a wonder the rig was working at all as there
were several of these defective capacitors on
|Test Equipment. -- you don't necessarily need to spend a great deal now adays. Some of these testers work very well and they
are about $20 to $30 or so from ebay.