Re: Topband: Front End Filters

2016-12-23 Thread Raoul Coetzee via Topband
surely it is important to have the correct loading on the crystal,  just connecting a crystal in the antenna path is not so good?It seems good loading is around 1-3k. Merry Christmas to all.Raoul ZS1C  From: K1FZ-Bruce To: topband@contesting.com; Dave

Topband: Front End Filters

2016-12-23 Thread K1FZ-Bruce
  The one they are  developing for marketing 'can' have 1 KHZ segment crystals channels..   I would encourage anyone to insert a single crystal in their receiver antenna input to see the difference before considering a purchase.  (Careful not to transmit into the experiement) 40 meters is a

Re: Topband: (no subject)

2016-12-23 Thread JC
DON’T OPEN THE LINK IT NOT FROM ME. IT MAY BE A VIRUS! From: 'topband' [mailto:topband@contesting.com] Sent: Friday, December 23, 2016 8:33 PM To: n...@comcast.net Subject: "Re: Topband: Radio World; Noise Floor; Where do we go from here?" JC doc

Topband: Front End Filters

2016-12-23 Thread Dave
About 15 years ago I built a switchable front end crystal filter, I was going to market it but it was too expensive for the Ham market. It covers 1800 to 1850 in 5kHz segments with a slight overlap so that there are no gaps, each section is a half lattice, the insertion loss is about 6dB but that

Topband: "Thinking out loud" - Something else to Think About (REV)

2016-12-23 Thread Dave Bowker via Topband
Crystal filters are nonlinear passive devices by nature of the characteristics of the crystal(s).  The motional characteristic of a quartz crystal is a function of the level of the signal applied to it, known as drive level dependence or (DLD) in engineering terms.  Crystal filters can

Topband: "Thinking out loud" - Something else to Think About

2016-12-23 Thread Dave Bowker via Topband
Crystal filters are nonlinear passive devices by natureof the characteristics of the crystal(s).  The motional characteristic ofa quartz crystal is a function of the level of the signal applied to it, knownas drive level dependence or (DLD) in engineering terms.  Crystal filters can

Re: Topband: "Thinking out loud"

2016-12-23 Thread Mark Schoonover
I've spent some time using the MFJ-1026 noise canceler. It took some effort to get it to work, I had to come up with a much better noise antenna. I bought one of those 8' crappie poles from local big chain and spiral wrapped about 50' of wire on it. I mounted it in the clear as close to my

Topband: Fwd: RTTY Beacon

2016-12-23 Thread Joe Galicic
Response from Warren below. He was very strong so it was not a harmonic. He was there on purpose. Not sure if we have experimental frequencies below 160 meters ? - Original Message - Joe, Thanks for the report! Running abt 75W into an inverted L 73 Warren On 12/22/2016 4:55 AM,

Re: Topband: "Thinking out loud"

2016-12-23 Thread vk3io
Hi all. Very interesting "thinking out loud" topic. With regards to the 403 crystal front end unit system (it seems not yet available), it will obviously be quiet expensive, even much more than the Yaesu uTune system. With 15 or 30, 1 Khz bandwidth segments or 15 or 30, 3Khz bandwidth