Hi Steve, No answer for your question #2 - Elecraft sells packs of 25 screws for modest price, but shipping to U.K. and VAT (if applicable) may dictate otherwise. Maybe pose that question to John, G3PQA - he's done a lot of work on Elecraft radios for fellow hams in the U.K.
Before doing any tests on the PA module itself, go into the K2 secondary menu (tap Menu, then tap Display) and find the PA entry - it should be 'on' - you can also check the PA fan control for proper functioning. If the 100 watt PA is enabled and the problem persists, then the detective work ensues. On question #1: carefully remove the KPA100 100 watt PA module from the base K2/10. There is an internal RF feed from the base K2 to the KPA100, a speaker cable, a 12 V DC power cable, and a ribbon cable to the Control panel. The small plugs are 2-pin plastic with non-locking tabs, and are easy to remove. Be careful to label the two identical plugs for RF and 12 VDC feed - you don't want to swap these upon reassembly. You can lay the KPA100 alongside the K2 and keep it connected for powered troubleshooting - use a couple of books to raise the KPA100 up to the level of the K2 side panel. I would first check (with power supply off and disconnected) the resistance between the PowerPole terminals on the KPA100. If it's low, then you could have a shorted PA transistor (Q1 or Q2). There are additional resistance checks described in a table on p. 45 of the KPA100 manual - see the Support menu on the Elecraft web page for access to manuals - the KPA100 manual appears under the Classic Line link for K2-related manuals. Those checks require removal of the KPA100 module, hence my recommendation to pull it. You could do the PowerPole resistance check before removing the PA module, of course. If there's no PA transistor short, then there may be a problem in the diode T/R switch. This would take a bit more effort to test, so I would hold off until you've done the other resistance checks. Some radios have been damaged by lightning-induced overvoltages on the cables, and the T/R switch diodes have been mentioned in older posts. Given what you observed about case screws being corroded, I would unplug and plug those internal cables and inspect for corrosion when plugs are separated from their mates. 73, Mike, K8CN ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
