How to Tune a TS-520 for QRP

[KG4EKQ]

Hi, all:

Can someone explain in a very detailed way how to adjust the tune-up procedure for this rig for QRP work?

Also, is there a universal method for doing this on typical boatanchors?  I'm borrowing this TS from a friend, but I'd like to try tuning down on my Swan 500CX back home as well.

In case you're needing circumstantial info:  I can't use the TS at full power because I'm in a ground floor dorm room on a college campus (middle Tennessee), and I'm having to use an inside antenna.  An outside one is absolutely not an option.  Thus, I'm afraid of RFI just wreaking havoc on surrounding phone lines, computers, etc., etc.

Based on this info, can someone advise as to the highest recommended wattage and how to tune the TS to get it?

Thanks so much!
Danny, KG4EKQ

[NJ0E]

just adjust the carrier level control for the power
output that you want. it's the "outer" knob on the
same shaft with the 'MIC' control on the "inner"
knob. as i recall, it's labeled 'CAR'.

i used a ts520 for qrp operation using this
method many times.

scott nj0e

[KG4EKQ]

Thanks, Scott.

Do you adjust the carrier level AFTER the tune up procedure when the rig is already totally ready to transmit?  I'm guessing so, and you just monitor your wattmeter as you adjust so as to reach the desired power level.

Danny

[NJ0E]

either method should work pretty well.

it's difficult, though, to "dip" the plate current
at qrp levels because the plate current will be so
little above the 60 ma "idle" level. you can adjust
the plate tuning and loading while monitoring the
output power on a wattmeter at qrp power levels,
though.

the ts520 is really a very nice radio; i bought
mine new in 1977 and still have it. only recently
have i replaced it as my main rig with a new (well,
second hand) main rig (a ten tec omni 6). the main
reason i replaced it is the clicking relay annoyed
me when keying the vox while operating cw (i use
cw ~95%), and i wanted 30 meter coverage very badly.

i hope you get alot of enjoyment from your ts520
operating qrp. qrp/ssb can be very frustrating,
though. give qrp/cw a shot; it's a hoot!


73
scott nj0e

[KG4EKQ]

Will try both methods - as soon as I secure a dummy load.  My antenna situation is wretched:  restricted to putting something up inside my ground floor dorm room.  Any antenna in here will not be a suitable load for tune up procedure.  I will let you know what happens with both recommended methods.

Thanks again,
Danny

[NJ0E]

hi danny,

another alternative you might enjoy is obtaining
one of the small, low power qrp cw transceivers
that are on the market today. you could take one
of these, a gel cell battery (or even a pack of
9 or 10 aa alkalines), a portable antenna (like
an end fed half wave wire), and a small tuner,
find a secluded spot under a tree on campus
somewhere, hang your antenna from a limb, and
make some qsos. i sure wish these had been
available when i was at university; they would
have been perfect!

many rigs of this type are available; here are a
few:

http://www.smallwonderlabs.com/
http://www.fix.net/~jparker/wild.html
http://www.tentec.com/Ttqrpcw.htm
http://www.elecraft.com/
http://www.mtechnologies.com/ohr/ohr100a.htm

i have a couple of the ten-tec t-kits, a small
wonder labs sw40+, and small wonder labs rockmites
for 40 meters and 20 meters. i enjoy operating
them off batteries while on backpacking trips.

here are a couple very small tuners:

http://www.amqrp.org/kits/blt/index.html
http://emtech.steadynet.com/zm2.shtml

i have the emtech zm-2; it works great. i'm sure
the blt is nice, too.

i have no affiliation with any of these outfits;
i just thought having a setup like this would
liberate you somewhat from the antenna constraints
of a dorm room.

much more information about this type of setup is
at http://ae5x.com

73 es have fun!
scott nj0e

[KG4EKQ]

Thanks again for the add'l advice, Scott.

I want to absolutely sure the rig and the price are right before I go into a new rig.  There are just too many options out there.  I also have to be sure it's sensible for me to buy a new qrp rig when I have a perfectly good, albeit qro, borrowed ts right here.  I'll check out those websites you suggested.  Keep the suggestions coming if more ideas hit you.  I'll keep you posted on the results here in the dorm room, although I don't see getting on air for a little while (station ass'y).

Danny

[ON4MGY]

Hi Danny,

The easiest (and I think best) way to do this is to add a negative voltage to the ALC connector. If you want you can go down below 1 watt output, so QRPP.
Take a look at

      http://www.mods.dk/view.php?ArticleId=739


and you'll see how to do this easily. No danger for your tubes also! Just tune as you do normally, and then use the negative tension to adjust to the power you want.

GL and 73

Nic ON4MGY
 

[KG4EKQ]

Nic,

I have seen that mod on that mods website.

What gauge wire should be used for this?  Is ordinary alligator clamp wire okay?

Thanks,
Danny

[ON4MGY]

Hi danny,

that wire will be ok.
There will only be a small current so absolutely no needs for thick wires.
Succes with it

73

ON4MGY Nic