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Title: Question - Johnson Ranger 1 Problem Post by: W1UJR on April 01, 2005, 06:39:34 AM Hi guys (and gals),
My Ranger 1 seems to have developed a odd problem. I was using it yesterday and all seemed fine until about 1/2 hour into operation. After about 1/2 hour I noted a "motor boating" sound in the receiver when the transmitter was not keyed. This would start out slow and then speed up until it covered up the stations I was listening to on the receiver. If I would key the transmitter then noise would stop briefly, then return in 30 seconds to to 1 minute. This only happens when the VFO is selected, if I use a xtal setting, xtal in the socket, no noise is noted. I suspect that a component in the VFO is heating up and failing, perhaps a capacitor allowing interstage leakage. My question is if anyone has run across this before, and if so what component failed? Due to the tight conditions of the Johnson VFO, I would like to minimize the surgery needed to diagnose and correct the fault. Also the rather delayed nature of the problem makes it somewhat difficult to repeat on the bench. The key thing here is that it only seems to happen with the VFO on, not in the xtal position, so it does seem to be a VFO fault. Your ideas, thoughts and suggestions? Thanks! 73 Bruce W1UJR Title: Question - Johnson Ranger 1 Problem Post by: Fred k2dx on April 01, 2005, 07:10:25 AM Bruce, did you try adjusting the VFO keyer?
Title: Question - Johnson Ranger 1 Problem Post by: W1GFH on April 01, 2005, 09:43:26 AM Yes it sounds like a switch, a relay, or component on the verge of failure is intermittently keying the VFO.
Title: Question - Johnson Ranger 1 Problem Post by: WA1GFZ on April 01, 2005, 10:40:51 AM It could be the screen voltage drifting around. You could be close to dropping resistor melt down or VR pube going south. My 122 vfo did the same thing just before the resistor opened up. This resistor was very under sized.
Title: Question - Johnson Ranger 1 Problem Post by: W2VW on April 01, 2005, 11:15:31 AM What happens if you move the VFO frequency away from where you are listening? Which Ranger 1 do you have?
Title: Question - Johnson Ranger 1 Problem Post by: Jim, W5JO on April 01, 2005, 04:59:24 PM To heck with it, just buy this one.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4673&item=5763787135&rd=1&ssPageName=WDVW Title: Question - Johnson Ranger 1 Problem Post by: W1UJR on April 01, 2005, 11:49:46 PM Well the mighty Ranger is fixed, somewhat.
Was able to simply turn the pot for the keyer tube, a 12AU7, and kill the motorboating. I think I have other issues as well as I can hear the oscillator running when the VFO switch is set in the XTAL 2 posisition. I have a 3885 rock in that socket, so looks like this thing may have a switch or wiring issue. I would think that I should not hear the oscillator running in the receiver when the switch is in the xtal posistion. This rig was really modified by a friend of mine, using most of Timmy's Ranger mods. He did a nice job, but I think things are not quite 100%. So, looks like more bench time for the rig. Tnx one and all for the suggestions on teh motor boating issue! 73 Bruce W1UJR Title: check the cap Post by: Tom W2ILA on April 02, 2005, 08:44:55 AM Bruce, AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
Be sure to check/change the electrolytic cap in the keying circuit. When this gets leaky it will let the VFO do its motorboating thing. The adjustment you did may stick but if you have the problem again the first place to look is that cap. It is under the keying chassis (assuming you have a Ranger 1 1/2 with the key ckt). We'll be look for you on the air this weekend with that Ranger. I finished up my Ranger last weekend so QRP has been the modus operendis here. 73 TM |