Re: [Elecraft] RF feedback into MH3 mic with KX3 on 2m

That didn't fix it. Found this lunchtime with a real antenna: - Worked OK with case open, testing the idea it was coupling from the 2m module itself. - Worked on other mic (SoundMagic earbuds and mic) - Touching the case with metal made interesting noises on receive. - HF (20m)

Re: [Elecraft] RF feedback into MH3 mic with KX3 on 2m

Yes. Headphone to mic distance gets short and feedback can happen from leakage. Sent from my iPhone ...nr4c. bill > On Feb 5, 2020, at 10:44 AM, Richard Corfield > wrote: > >  > Even with monitor running into headphones? > > I was running the contest with monitor off at first, but I

Re: [Elecraft] RF feedback into MH3 mic with KX3 on 2m

The metal shield cover on the 2m module was not flat but slightly raised at the edge. I have pressed this back on and the problem seems cleared. So I guess it was contacting or coming close to the circuit board on the control module, perhaps that giving the feedback loop for RF. Question is -

Re: [Elecraft] RF feedback into MH3 mic with KX3 on 2m

I've done some further tests and proven the problem is with the MH3. So I'll have to take that apart and look for the problem. The radio is fine with little earbuds/mic plugged in via splitter cable. Swap out the mic on the earbuds with the MH3 and leave all the rest the same and it goes wrong.

Re: [Elecraft] RF feedback into MH3 mic with KX3 on 2m

Even with monitor running into headphones? I was running the contest with monitor off at first, but I turned monitor on only in response to my contact telling me my audio was garbled. That said, I initially wondered if the garble was due to frequency drift not feedback. Though if it was a monitor

Re: [Elecraft] RF feedback into MH3 mic with KX3 on 2m

Turn down TX Monitor volume. Sent from my iPhone ...nr4c. bill > On Feb 5, 2020, at 5:23 AM, Richard Corfield > wrote: > > I had issues with RF feedback on the MH3 during the UKAC SSB 2m contest > last night. It seemed intermittent. Result was terrible noise in Monitor > output (my

[Elecraft] RF feedback into MH3 mic with KX3 on 2m

I had issues with RF feedback on the MH3 during the UKAC SSB 2m contest last night. It seemed intermittent. Result was terrible noise in Monitor output (my headphones) and to the other station, so it affects the audio input. With experiments at the time and this morning: - Occurs when RF

Re: [Elecraft] RF feedback problems with P3 and external keyboard

I might suggest that folks do not neglect that the RF may be getting into the keyboard, causing its microcontroller to crash. Remember that we live in an "Everything is a computer" world. - Brendon KK6AYI On Sun, Nov 26, 2017 at 10:22 AM, Jim Brown wrote: > Good

Re: [Elecraft] RF feedback problems with P3 and external keyboard

Good advice, Kevin, especially winding as many turns as practical.  I wouldn't add the extension unless a choke without it didn't solve the problem. 73, Jim K9YC On 11/26/2017 8:52 AM, Kevin Stover, AC0H wrote: The mix of the toroid's used does matter. Mix 31 is best. Here is what I did

Re: [Elecraft] RF feedback problems with P3 and external keyboard

ideals Gerald From: Kevin Stover, AC0H Sent: Sunday, November 26, 2017 10:54 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] RF feedback problems with P3 and external keyboard The mix of the toroid's used does matter. Mix 31 is best. Here is what I did with a USB mouse. I bought four mix

Re: [Elecraft] RF feedback problems with P3 and external keyboard

The mix of the toroid's used does matter. Mix 31 is best. Here is what I did with a USB mouse. I bought four mix 31 snapon's and installed two 18 inches back from the mouse and another pair 18 inches back from the connector, winding as many turns as would fit. I bought a USB extension cable

Re: [Elecraft] RF feedback problems with P3 and external keyboard

with your P3 issue. 73, Alan. G4GNX -Original Message- From: ANDY NEHAN Sent: Friday, November 24, 2017 8:34 PM To: elecraft@mailman.qth.net Subject: [Elecraft] RF feedback problems with P3 and external keyboard After LOTS of experimentation I think I have found that just recently I have

[Elecraft] RF feedback problems with P3 and external keyboard

After LOTS of experimentation I think I have found that just recently I have some RF feedback into the usb keyboard on the rear of the P3. This manifests itself particularly badly with the Genovation keyboard but is also present with a standard usb keyboard. Oddly enough it is MUCH worse when

Re: [Elecraft] RF feedback? only when using KXPA100

In looking back at my original post..I omitted the word NOT. Thus "all PL-259 connectors are not all created equal". Sorry folks, and thanks Jim for catching the over site. 73 Bob, K4TAX On 8/8/2017 12:42 AM, Jim Brown wrote: On 8/7/2017 3:06 PM, Bob McGraw K4TAX wrote: PL-259

Re: [Elecraft] RF feedback? only when using KXPA100

On 8/7/2017 3:06 PM, Bob McGraw K4TAX wrote: PL-259 connectors are all created equal. This is definitely NOT true. There are as many cheap knock-offs as there are cheap factories and cheap vendors. There are tolerances on diameters of the center pin and center receptacle, there are

Re: [Elecraft] RF feedback? only when using KXPA100

A comment on tuners. The SWR and associated increased loss remains the same on the feed line regardless of the action of the tuner.When using a tuner, the load only looks better to the transmitter and the tuner presents added overall loss. Reflected power is not totally lost power. Only

Re: [Elecraft] RF feedback? only when using KXPA100

Concur on suspecting cables as first step for most problems. Also suspect the meter that measures the signal/voltage/current/etc. Or other items in the line. I ran into a similar issue using an antenna tuner on 2m. I had just put up a 11-element yagi (not real high but equivalent to the

Re: [Elecraft] RF feedback? only when using KXPA100

Just as a comment. PL-259 connectors are all created equal. Some are great looking connectors and are just pure crap! The plating makes for good looks but poor performance. To that end, I always and every time snug my PL-259 connectors with a pair of 4" Channel Lock pliers. Finger tight

Re: [Elecraft] RF feedback? only when using KXPA100

Jim - I recently sent my K3 to the 'Mother Ship' for some upgrades while my wife and I took a 3 week road trip. I hooked up the returned rig over the weekend. Much to my chagrin, I was extremely high SWR. I verified that I had the RF path correct from the K3 through assorted other devices and to

Re: [Elecraft] RF feedback? only when using KXPA100

On 8/6/2017 5:25 PM, David F. Reed wrote: It was a connection to my coax switch; take it out of line, it goes away. re-connected, it comes back. Cleaned the connections and reconnected, it is gone. Many years ago, a very smart guy said something it the effect that with any problems with TX

Re: [Elecraft] RF feedback? only when using KXPA100

Great news; found it! It was a connection to my coax switch; take it out of line, it goes away. re-connected, it comes back. Cleaned the connections and reconnected, it is gone. Hurrah! 73 de Dave, W5SV On 8/6/17 12:12, Mike Flowers wrote: Good to find the root cause. Fix will be an

Re: [Elecraft] RF feedback? only when using KXPA100

Make sure you have not accidentally enabled Ant 2 on the KXPA100. -- View this message in context: http://elecraft.365791.n2.nabble.com/RF-feedback-only-when-using-KXPA100-tp7633145p7633156.html Sent from the Elecraft mailing list archive at Nabble.com.

Re: [Elecraft] RF feedback? only when using KXPA100

Mike, it is clean on a dummy load; I guess I need to track down if I have lost my ground somewhere, or find the feedback path... 73 de Dave, W5SV On 8/6/17 00:13, Mike Flowers wrote: Hi Dave, Have you tried this using a dummy load? May be useful to eliminate RFI as a cause. -- Mike

[Elecraft] RF feedback? only when using KXPA100

This did not used to happen; it is new to my set-up, nothing I am aware of has changed... When trying to operate JT65, if I set the power to 10 watts, everything is fine (KXPA100 is not active). If I set to anything above 10 watts (yeah, like 11 watts or more), I get bad RF feedback (sounds

Re: [Elecraft] RF feedback?

assistance is greatly appreciated. James K2QI -Original Message- From: Monty Shultes [mailto:mon...@mindspring.com] Sent: Tuesday, July 14, 2009 7:11 AM To: K2QI Subject: Re: [Elecraft] RF feedback? James, Is the wattmeter between the SB220 and antenna or between the rig

Re: [Elecraft] RF feedback?

On Tue, 14 Jul 2009 13:44:00 -0400, K2QI wrote: I am curious though; your previous email mentioned rectification of audio in the wattmeter, feedline or antenna. As noted, one or more good common mode chokes are in order. You mentioned the lack of a station ground. That is a lightning safety

Re: [Elecraft] RF feedback?

Hi Monty, I too have assumed that RF from the antenna was causing the issue, but why can't I recreate the problem when transmitting a constant carrier? The behavior of this phenomenon is strange to say the least. What usually happens is the SWR alarm will activate upon initial keydown in SSB

Re: [Elecraft] RF feedback?

Hi Jim, Thanks for the reply. I have not noticed any power fluctuations or increases in reflected power during the alarm event. Antenna system is a Tarheel 100A screwdriver mounted on a tripod on my balcony. The balcony is about 40 feet away from the station. The antenna is fed with good

Re: [Elecraft] RF feedback?

Hi Myles, The microphone is the stock Elecraft hand mic. There is nothing betwen the microphone and the rig. I'm home now and doing some more tests and noticed something odd. Upon initial keydown in SSB with the amp on and the K3 set to 50w, I'll get a forward reading on the wattmeter anywhere

Re: [Elecraft] RF feedback?

Don, if that were the case wouldn't this problem manifest itself during a constant carrier keydown, and not just in SSB mode? Anyway, just to eliminate the feedline I took the dummy load outside and connected the antenna feedline directly to it. I was previously using a patch cable from the meter

Re: [Elecraft] RF feedback?

Well, at this point it looks like it may have something to do with the meter itself. I turned off the peak function and now it works fine without the alarm going off; even with it set to 1.5:1. Turning the peak function back on, and blam... alarms galore. James K2QI

Re: [Elecraft] RF feedback?

On Tue, 14 Jul 2009 18:26:15 -0400, K2QI wrote: Antenna system is a Tarheel 100A screwdriver mounted on a tripod on my balcony. The balcony is about 40 feet away from the station. The antenna is fed with good quality Times Microwave LMR-400UF. The last 20 feet of it were wound into a common

Re: [Elecraft] RF feedback?

James, I did not mean to imply (or state) that the coax was any problem. The real problem is that you are driving very high power into a small antenna, and you have not provided a good RF Ground at the base of that antenna. The net result is that you have high level RF floating on most

Re: [Elecraft] RF feedback?

. James K2QI -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Jim Brown Sent: Tuesday, July 14, 2009 9:13 PM To: Elecraft Reflector Subject: Re: [Elecraft] RF feedback? You're running 1.1kW to a screwdriver with essentially

[Elecraft] RF feedback?

I've noticed that I get some sort of RF feedback spike when using the SB-220 and keying up in sideband mode. It's enough to trip my SWR alarm in my wattmeter. What is odd is that it doesn't happen on keydown CW. The problem also gets worse when keying up in sideband mode with mic gain turned

Re: [Elecraft] RF feedback

The way I explain it is to say If your roof leaks only when it rains, do you blame the rain or the roof? David G3UNA A PR problem exists here. It is difficult to get a consumer to understand why his brand new (whatever) is malfunctioning. The problem happens only when you transmit,

RE: [Elecraft] RF feedback

On Fri, 5 Dec 2008 13:31:57 -0800, Jack Regan wrote: I let you know the grounding works out. It's NOT about grounding. But matters a LOT about how you connect cable shields. Yes, the K3 has a Pin 1 problem. Read about it in the tutorials below. Free, no cookies, no advertising.

[Elecraft] RF feedback

I'm running the K3 with an Ameritron AL800 and a Steppir 3 element with 40m dipole add-on. I have a severe though intermittent feedback problem on 40m that I did not have with an Icom 751a. The feedback only occurs when I'm using the amp (even with very low drive). I've common core choked

Re: [Elecraft] RF feedback

Richard S. Lindzen wrote: I'm running the K3 with an Ameritron AL800 and a Steppir 3 element with 40m dipole add-on. I have a severe though intermittent feedback problem on 40m that I did not have with an Icom 751a. The feedback only occurs when I'm using the amp (even with very low drive).

Re: [Elecraft] RF feedback

In a message dated 12/5/2008 9:05:02 A.M. Pacific Standard Time, [EMAIL PROTECTED] writes: I'm running the K3 with an Ameritron AL800 and a Steppir 3 element with 40m dipole add-on. I have a severe though intermittent feedback problem on 40m that I did not have with an Icom 751a. The

RE: [Elecraft] RF feedback

Dick, I have an 811-H connected to my K3 running 500 to 600 watts cw. I have problems that might be similar to yours. I get loud, fuzzy, cw tones on both my noise canceling head phones my external speakers. Both these items are powered devices. One by a wall wart and one by an AAA battery.

Re: [Elecraft] RF feedback

Gentlemen - No amount of adding low-pass filters, inserting antenna tuners, grounding your set, etc. will clear up these problems. Don't let anyone tell you different. Facts is facts, and that's that. While all these steps are good things to do, and follow what is commonly known as

Re: [Elecraft] RF feedback

- Original Message - From: Vic K2VCO [EMAIL PROTECTED] To: Richard S. Lindzen [EMAIL PROTECTED] Cc: elecraft@mailman.qth.net Sent: Friday, December 05, 2008 6:10 PM Subject: Re: [Elecraft] RF feedback There is a so-called pin 1 problem in the K3's mic input circuitry. The fix

Re: [Elecraft] RF feedback

- From: Vic K2VCO [EMAIL PROTECTED] To: Richard S. Lindzen [EMAIL PROTECTED] Cc: elecraft@mailman.qth.net Sent: Friday, December 05, 2008 6:10 PM Subject: Re: [Elecraft] RF feedback There is a so-called pin 1 problem in the K3's mic input circuitry. The fix is to jumper L4 on the front panel