[Elecraft] High Tx IMD with new K3s/10

I recently got a new K3s/10 built up and running. This week I ran some tests to get familiar with it and one test that surprised me was the high Tx IMD levels. I first noticed that the two tone waveform on a Tek o'scope showed flat topping starting at about 4.5 W. As the power level was increased

[Elecraft] Where is the K3s setup for JT65 info?

I saw this info on one of the websites a few weeks back but I can't find it. Thanks, Bill N0CU -- View this message in context: http://elecraft.365791.n2.nabble.com/Where-is-the-K3s-setup-for-JT65-info-tp7621127.html Sent from the Elecraft mailing list archive at Nabble.com.

Re: [Elecraft] Where is the K3s setup for JT65 info?

Ken, I am using the USB interface to the computer and am having trouble figuring out how to set the audio levels for WSJT-X: -On receive the decoder is saturated. I have to drop the gain slider in WSJT-X to zero to be able to decode any signals. I haven't found any other adjustment for the

Re: [Elecraft] Where is the K3s setup for JT65 info?

That's it. Thanks Howard. -- View this message in context: http://elecraft.365791.n2.nabble.com/Where-is-the-K3s-setup-for-JT65-info-tp7621127p7621149.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing

[Elecraft] K3s/10: Max FP temp?

I am starting to use some digital modes and couldn't find any specs/guidelines on max power, duty cycle or FP temp. Running only 5W on JT65 (ie, 50% duty cycle) I see the FP temp get up to 43C after just one or two QSO's. Is an external fan recommended when using high duty cycle modes? Thanks,

[Elecraft] K3s Crystal Filter Config Qustion

I am uncertain on how to configure the radio's filters using the K3 Utility. I have the 6 KHz & 2.8 KHz filters. I am totally confused by Cady's book, which shows (pg 27) almost all of the ENABLE boxes checked. This doesn't make any sense to me since I doubt the hardware can be configured with all

[Elecraft] Strange problem with K3s/10: could use some suggestions

I am having a strange problem with my K3s/10: the max output power on 20M drops from 11.5W to 7.5W as the freq is moved from 14.0 MHz to 14.35 MHz. All of the other bands stay above 11W across their respective bands. The other interesting characteristic is that if I lower the power to 5W, there is

Re: [Elecraft] New K3/K3S Beta Firmware, rev. 5.57: Faster response to high reflected power

I frequently wonder just how much protection a typical SWR protection circuit can provide against an instantaneous discontinuity if it relies totally on a feedback approach. If the response time of the feedback circuit isn’t faster than the risetime of the voltage at the output transistors that

Re: [Elecraft] High Tx IMD with new K3s/10

Benny, I recently had Elecraft replace a KLPA3A again. They also did the Tx IMD mod and an alignment. I am now seeing the following 3rd order IMDs: 4W -40 dBc 8W -40 dBc 9W -35 dBc 10W -30 dBc 12W -20 dBc What is also encouraging is that now the higher order IMDs (5, 7 & 9th) stay at

Re: [Elecraft] EFHW

The reason your antenna was a lot less finicky with a bit of coax is that the EFHW antenna requires a return path for the RF field. Theoretically, without a return path, the antenna won't radiate at all. The recommended setup for this antenna is for a .05 wavelength counterpoised to be used. EZNEC

Re: [Elecraft] Magnetic Loop question

"The polarization does not matter to radiation pattern. " This isn't the case for most antennas we use which launch an electromagnetic wave by generating an electric field. Ground characteristics affect the pattern of a vertically polarized wave much more than they affect a horizontally polarized

Re: [Elecraft] K3S QST Article

The official response I got from the factory is that to have any of the IMD mods done, the radio needs to be sent in to the factory. Bill N0CU -- View this message in context: http://elecraft.365791.n2.nabble.com/K3S-QST-Article-tp7623462p7623522.html Sent from the Elecraft mailing list

Re: [Elecraft] K3S QST Article

Wayne, For those of us with the unmodified KLPA3A (10 W module), can the mods be done by a skilled engr/tech. If so, can the parts be made available as a kit. If not, can just the module be sent in for modification instead of the whole radio. Bill N0CU -- View this message in context:

Re: [Elecraft] K3S QST Article

I was not surprised to see a comment about the Tx IMDs in the QST article. One of the first problems I encountered with my new K3s/10 was poor Tx IMD performance. What I observed was flat topping that started at about 5W, and progressively got worse as the power was increased. The distortion was

Re: [Elecraft] K3S QST Article

I would not expect the synthesizer (old or new) to be a contributor the IMD issue. Hopefully someone will correct me if that is a bad assumption. To me, the primary issue appears to be the linearity of the two RF power amplifiers. During the course of my troubleshooting, I noticed that a number

Re: [Elecraft] K3 Sub-Receiver, filters, I/O Board For Sale

Jeff, Is your sub-receiver still available? Bill N0CU -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-Sub-Receiver-filters-I-O-Board-For-Sale-tp7628405p7628593.html Sent from the Elecraft mailing list archive at Nabble.com.

Re: [Elecraft] BL2 -- Antenna Balun Usage

I am no expert when it comes to baluns, but here are several comments that are based upon some research that I have recently done on the subject: 1) Now, unlike in the past, the most commonly used balun is the current balun. Most current baluns use some type of transmission line (if they do, they

Re: [Elecraft] BL2 -- Antenna Balun Usage

I was going to respond to Jim’s comments about terminology, but Wes presented my thoughts better than I could have. I would like to address two of the comments that were made in the responses. First, EZNEC is powerful tool that can help understand theoretical behavior of ideal antenna systems.

Re: [Elecraft] Choking KPA500 and testing a box of unknown chokes

Jim, I apologize: I made a typo in my post. It should have said "...the highest choking IMPEDANCE is usually obtained with an air core choke (coax looped with or without some form like PVC)". Maybe this is an over-statement, but of the few chokes I have tested, air core chokes made with just

Re: [Elecraft] Choking KPA500 and testing a box of unknown chokes

Mike, Wes raises one of the many interesting aspects of balun design, and not surprisingly, one that there doesn't appear to be a consensus on. Two of the main trade offs are bandwidth and choking impedance. The highest choking BW is usually obtain with an air core choke (coax looped with or

[Elecraft] For sale: K3S/10 and P3

K3S/10-KS/N 10726Purchased: 27 Mar 2016 KANT3 KTCXO3-1(0.5 ppm) KFL3A-2.8(2.8 KHz) KFL3A-6K-IR(6 KHz) KBPF3A K3S/P3 book by Fred Cady $1775 P3 S/N 4197 P3SVGA $650 Both for $2325 Prices include shipping, all manuals, & cables Bill N0CU -- Sent from:

[Elecraft] For sale: K3S/10 and P3

*Both items have been sold!* Bill N0CU -- Sent from: http://elecraft.365791.n2.nabble.com/ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: