Low Pass Filter problems
#8
(2016-10-21, 16:34)allsorts Wrote:
(2016-10-21, 08:21)DrRobin Wrote: I have found the schematics.  It looks like a problem with one of the multiplexers or signal lines when the filter is selected on the E channel.  I will have to trace through with a scope probe. 

Does "been all around the chip" mean a visual inspection or a reflow of each pin with fresh flux? Apart from the chip I missed actually soldering a complete side (Doh!) I had "fun" with one of the others, every pin looked well flowed and connected but a reflow cured the problem so obviously something wasn't properly soldered. I have a feeling that there is some form of protective substance over the bare solder or plated areas as putting the through hole stuff on didn't "take" as quickly as I'd expect.

As for settings that's just getting a balance between the conflicting variables: interference, noise floor, bandwidth (faster rise time), filter delay, etc. For the last couple of days I've been in manual with minimal filtering (54 kHz on Ch1 (null to Anthorn), 19kHz on Ch2 and 54 kHz on the E-field. It was working quite well. Note "was" I've fiddled with antenna orientation and given it a supply earth connection today and it doesn't appear to be working as well as it was.  B-(

which chip and component had the welding problem?
Stations: 1654
Reply


Messages In This Thread
Low Pass Filter problems - by DrRobin - 2016-10-20, 19:54
RE: Low Pass Filter problems - by DrRobin - 2016-10-21, 08:21
RE: Low Pass Filter problems - by allsorts - 2016-10-21, 16:34
RE: Low Pass Filter problems - by Ranieri - 2016-10-22, 07:14
RE: Low Pass Filter problems - by DrRobin - 2016-10-21, 22:17
RE: Low Pass Filter problems - by allsorts - 2016-10-21, 23:53
RE: Low Pass Filter problems - by allsorts - 2016-10-22, 18:55
RE: Low Pass Filter problems - by DrRobin - 2016-10-25, 21:23
RE: Low Pass Filter problems - by allsorts - 2016-10-25, 22:14
RE: Low Pass Filter problems - by DrRobin - 2016-10-31, 22:18
RE: Low Pass Filter problems - by DrRobin - 2016-11-02, 17:56
RE: Low Pass Filter problems - by DrRobin - 2016-11-02, 18:05
RE: Low Pass Filter problems - by allsorts - 2016-11-02, 22:04

Possibly Related Threads…
Thread Author Replies Views Last Post
  Vin too low mt007 3 22,324 2016-12-04, 12:40
Last Post: allsorts
  Low gain on this system (Waregem) Noodweer Benelux 9 52,767 2015-07-18, 03:09
Last Post: JamesPatterson
  New station, very low stroke number Gianfran 2 18,481 2014-12-27, 09:47
Last Post: cutty
  Low effectivity Snicker 13 79,108 2014-07-30, 21:24
Last Post: W3DRM

Forum Jump:


Users browsing this thread: 2 Guest(s)