
 ALC on TS440 => hint..

de DL5MFK @ DB0AAA

de: Axel DL5MFK @DB0BOX from Donauwoerth JN58JR DOK T09

Hello OM's and TS-440 owners!
Imagine you own a transverter, e.g. 10-to-2-meter-band, only rating abt. 500
mWatt Input...
Now, try connect it to the 440 - it will work !!(what else did u expect?!)
But - to get the power on 28mc to 500 mWatts is a very complicated thing,
because the knob for MIC-gain and Carrier is very hard to adjust on these low
levels...
Now, remeber the handbook - wasn't there somewhere something mentioned about
the ALC? YES it IS!!! the REMOTE-Connector gives a direct access to the
ALC-ciruitry, just put in -3 to -11 Volts in, and enjoy the easy low-power-
-regulation... BUT!!!!
HOW DO I GET A (compared to GND="-") NEGATIVE tension?! (even in mobile
operation...)
Well, there a little IC's that convert RS232-lecel to TTL...
Get it? they produce out of 5Volts source +/- 12 Volts...
So, take e.g. an MAX"#", an BC 547, a 5Volt Zener-diode and an 2k2ohms resistor make a 5V-mini-supply and build it together with the 4 capacitors needed round the MAX 232... Connect e.g. pin 10 to +5V, and load pin 7 with an trimmer 4k7 ohms to ground; the middle pin of the trimmer now gives you an
ALC-supply of -0 to -11 (or more, depends on supply of MAX232!) Volts, which
now can drive the ALC, and regulate it MUCH better in low-power!
BUT!!! the MIC and CAR-regulators are still in function!!!!!!! mind that
try it, the higher the neg.tension on ALC-in, the lower the power!
Mine works ufb with an Microwave-Modules 28/144 SSB transverter!
73's de Axel, Donauw|rth es hpe cuagn!

de: Axel DL5MFK @DB0BOX from Donauwoerth JN58JR DOK T09

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