All, Here is the statement from the developer of the SPE Expert 1K-FA - regarding ALC, quoted from an early Expert Reflector:....
I hope this will clarify the SPE Expert vs K3 - and ALC !! Please excuse me if I step on someones toes...... quote *The Elecraft K3 had positive-going ALC, too. In helping them test their* *conversion of the K3 to negative-going ALC with different amps, I received* *an email from Gianfranco, copy below. His thoughts on how the SPE Expert is* *designed to handle transceiver drive may apply here to the Ten-Tec.* * * *FWIW,* * * *Bob* *K5LLF* * * *Hello Bob,* * * *Elecraft has a strong reputation for manufacturing cost effective and* *quality transceivers, and for this I'm glad that they decided to conform* *with the state-of-the-art negative ALC how is commonly intended by all the* *other manufacturers.* * * *As you well know the ALC is a transceiver's input used to adjust its output * *power during transmission: at 0 Vdc there is a maximum power emission and,* *little by little the control voltage decreases toward negative values,* *output power emission is reduced until it becomes practically nothing at a* *given BV (Break Voltage) control voltage.* * * *Every brand has a different BV (ICOM: -3/-4 Vdc, YAESU: -4/-5 Vdc,* *KENWOOD: -8/-9 Vdc; etc.).* * * *In order to have the widest possible coverage, all the linear amplifiers'* *manufacturers state that the maximum ALC voltage excursion sourced by their * *devices is -11 Vdc.* * * *>From this perspective Elecraft's choice (0 Vdc: max PW; -4 Vdc: min PW)* *sounds good then, but a very important detail to take into account is the* *overall intervention time which has to be the shortest possible!* * * *All the ordinary linear amplifiers have an external potentiometer which sets* * * *a given threshold (manually adjusted by the user) whose purpose is to avoid * *the linear amplifier's over-driving when that threshold is exceeded.* * * *SPE EXPERT 1K-FA is quite different from those because is fully automatic* *within its working: ALC control is not only for avoiding over-driving* *situations, but it is also intended as a system for adjusting the optimal* *output power for a perfect driving of the transceiver itself.* * * *We really suggest to always leave the transceiver's output power manual* *control to its maximum level because the EXPERT, thanks to its exclusive* *design, will provide to control that level as long as the required optimal* *value will be reached.* * * *Don't try to analyse the ALC control voltage of our linear amplifier because* *it cannot be measured using ordinary methods as it operates dynamically for * *assuring a great linearity.* * * *Elecraft has only to implement a very fast input able to deal with negative * *voltages as all the other manufacturers already do: SPE's amplifier will* *adapt to that in order to work for the best possible linearity.* * * * * * * *73's* * * *Gianfranco I0ZY* unquote _____________________ 73 de LA8AW - Odd-Egil _____________________ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
