Those are my thoughts also. Follows is my way of isolating the "shock" of an 80 amp audio modulated load from my K3 input power supply.
I do run my radio bench with a 70 amp linear Astron supply BUT I have a seperate Power supply buss(pair) and a battery buss(pair)(plus a seperate ground buss bar). The two busses are connected to each other by a knife style disconnect from an air-conditioner cutoff (new and removed from box and mounted under bench) BUT there is 25 feet or wire involved and the spare wire (about 20 of the 25 feet) is coiled up as a sort of (wimpy) inductor. BTW, the 4 buss bars (2 bar pairs) are 1/4 by 1 inch aluminum and the ground buss is 1/4 by 1 inch copper mounted on the upper back of my bench. The wire is long and is 14 ga on purpose to add resistance to partially isolate the "shock" of the 80 amp requirement (during audio peaks) of the ALS500 solid state amplifier. The amp is wired to the battery buss with 3 pairs of 12 ga wires (14 inches) and the battery buss is wired to the battery also with 3 pairs of 12 ga wires (12 inches). The battery is two LARGE automotive batteries (one stolen for my truck recently not yet replaced). (Flame on about gasses if you wish, I'm not listening) I don't want that shock on the power supply AND I don't want my K3 to have to try to operate properly on that kind of voltage that must be very noisy (and it matters not if the power goes out, I keep on operating). The battery buss (and batteries) is held up in non-use times by a battery maintenance charger (of no use during operation). Not one of the $7 ones that are useless on this size battery (if any), these are about $30 and are larger and "intelligent" and monitor and only add charge as needed. 73, de Jim KG0KP ----- Original Message ----- From: "Dave Hachadorian" <k...@arrl.net> To: "Elecraft reflector" <elecraft@mailman.qth.net> Sent: Wednesday, March 11, 2009 11:53 PM Subject: Re: [Elecraft] K3: Do you "Juice" your K3? > Earlier today, I remarked that one of my K3's was running > warm in the NAQP RTTY after an extended number of RTTY CQ's. > Tonight I did a little experiment - key down at 100 watts > for four minutes while noting PA Temp and fan speed. It > turns out that there really is no problem. Both K3's behaved > identically and both leveled off at PA Temp = 64C after > about 3 minutes. For the record, here are the results (best > viewed with Courier font): > > Time Temp Fan > 0:00 26C 0 > 0:26 37 1 > 0:44 41 2 > 1:19 50 3 > 1:45 55 4 > 2:40 60 4 > 2:50 62 4 > 3:15 64 4 > 4:00 64 4 > > Room temp was 77F. > > Dave Hachadorian, K6LL > Yuma, AZ > > ______________________________________________________________ > 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 > ______________________________________________________________ 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
