Re: Topband: Any experience with 2N3553?
I would certainly be interested in how the Asia 5109's checkMy experience with Asian semiconductors has not been 100%...Hal/WB4AEG On Thu, 19 Mar 2020 14:42:24 -0400 Richard (Rick) Karlquist wrote On 3/19/2020 10:04 AM, Don Kirk wrote: > For grins and giggles I ordered 10 2N5109 parts on E-bay (from Asia). Also > ordered new ones from Mouser which I just received today, and also had one > that I purchased a long time ago from Mouser (all of my Mouser purchased > Just FYI, > Don (wd8dsb) > _ I used the 2N3553 45 years ago as a medium power RF amplifier, but not as a 2N5109 substitute. I don't know that it has the high and flat current gain and the low base spreading resistance of the 2N5109 family. That didn't matter for my application. Remember that Motorola stopped making 2N5109's in the year 2000. Therefore any transistor with a Motorola logo and a date code newer than 2000 is a prima fascia counterfeit. I just received 20 each of the Central Semiconductor 2N5109's from Mouser. If I were going to evaluate transistors claiming to be 2N5109, I would want to check: 1. DC current gain (beta), both the peak value and the uniformity of beta vs collector current. 2. f-sub-T 3. Base spreading resistance. This is determined indirectly by measuring noise figure. Depending on the application, one of more of these could be important. Rick N6RK _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: No DXwatch cluster for two days now?
Don't know but experiencing same here...Thought it may have been my problemHal/WB4AEG On Fri, 23 Feb 2018 14:02:36 -0500 Guy Olinger K2AV k2av@gmail.com wrote The RBN reports and filters are gone as well. Usually a break like this indicates a difficult upgrade, or some problem they haven't figured out yet, or both. Perhaps Pete has some inside dope? 73, Guy K2AV. On Fri, Feb 23, 2018 at 1:39 PM, terry burge k...@comcast.net wrote: Anyone got any idea what is going on with DXwatch side? Haven't been able to pull it up for two days and had to shift to DXSummit.fi. Personally, I hope it will be back on for this weekends 160M CQ SSB contest. I always enjoy that one when I can get on it and bump head with the big boys. Terry KI7M _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: WKYW on 1810kc
S 5 or so here in Georgia...Hal/WB4AEG On Wed, 10 Jan 2018 17:59:36 -0500 Bill Stewart cw...@embarqmail.com wrote Is anyone copying a AMBC stn around 1810kc. They are 30db over S9 here. The sig was cutting in and out but for last few mins. has been on full time. Did hear them mention '1490' and Frankfort KY. Web info comes back to WKYW. Heard them yesterday as well. Tnx de Bill K4JYS Near Smithfield, NC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
