To sum things up... As stated in Ray's post
/g/la1k/message/1261 an SWR as high as 2:1 is acceptable, and yet Paul (NO0T) observed that his LA-1K went to bypass as SWR went to 2:1 to protect the finals.? This clearly demonstrated yet another case of
inferior design implementation found on the LA-1K amplifier.
In his defense of the LA-1K, Kent (K9ZTV) writing, in part, "My Elecraft KPA500 folds back to half-output at 2:1 and goes into the red zone (cautioned as "critical" in the manual) above 2:1." in his post
/g/la1k/message/1262 yesterday.? But, the KPA500 Owner's Manual: states, in part, on Page 35 "
For ease in reading the critical SWR levels, the SWR LEDs are green from 1 to 1.5. The 1.5 to 2.1 SWR LEDs are yellow and the LEDs for SWRs above 2.1 are red."? It is important to note Elecraft stating that "LEDs for SWRs above 2.1 are red" as opposed to "goes into
the red zone (cautioned as "critical" in the manual)
above 2:1" as Kent observed in his Elecraft KPA500.
In an attempt to obtain clarifications from Kent in my post
/g/la1k/message/1264 yesterday, of which I haven't received a response as of this writing, I had amended it to point out that the Owner's Manual of the Elecraft KPA1500 (their top-of-the-line amp/ATU machine) states "
SWR bargraph: The SWR LEDs are green from 1 to 1.5. The 1.5 to 2 LEDs are yellow and the LEDs above 2 are red" and "The bargraphs are color-coded green for normal, yellow for marginal and red for excessive levels.? Excessive levels may trigger a fault and switch the KPA1500 to STBY" on Page 18 and Page 27, respectively.? It is important to note the Elecraft KPA1500 may trigger a fault and switch to STBY if and only if it encounters excessive levels (above 2:1) of SWR.
An SWR
as high as 2:1 is acceptable for the Elecraft KPA1500.? SWR reference material for all to consider:
73,
Ray
KJ5MI
