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Just put a choke on the feedline before it enters the shack.... I usually use a mix 31 torrid with about 10 turns and never have had an issue.

DB, Yes, the primary is bifilar, so the two conductors are tightly twisted together. As far as band use....this works great from 80-10m. You're using a wire that is multiple-harmonic of the half wave frequency. So if you have something in the 130-134' range, you'll get from 80-10m. Since I'm...

Folks, I built a couple of 49:1 unun transformers attached to a 130' wire. Amazing of how well this works. Primary has 2 bifilar turns, and secondary is total of 14 turns. Some great references out there such as https://elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/ The...

Thanks for the explanation; this makes sense. I guess I could add a first stage amp to drive the second if I didn't want to bias the base of that transistor to improve efficiency? What about impedance matching? Should I consider an LC network on the input so I'm around 50ohms? This is assuming...

Folks, Playing around with building a VHF Class C amplifier and using this schematic as a baseline http://electronics-diy.com/1W_Universal_RF_Amplifier.php After building this per the schematic, I'm not getting any gain! If I add some biasing to the base of the transistor with a 20K...

So I've got a lot of the noise filtered now across the bands except one particular source that is very repeatable. On 80/75meters I have noise every ~26Khz when I have the single circuit on going to the shop which is a LONG run - ~ 150'. Even with nothing turned on (unplugged) I get noise...

Folks, I found two more noise sources. A fan in the shop that is for ventilation. It creates a birdie every 27Khz. Any thoughts on how to filter this? I also have another switcher for some networking equipment for a -48VDC equipment. It's creating a lot of hash. I've tried to use multiple...

Not at all. Guy came out and we chatted - nice fellow. He noted that the noise got worse by my house o_O and we just laughed. There is some noise down by the power pole and down the road as I walk the lines. But we've come down from an S9 to around an S2 by just cleaning my noise up - which is...

Gary, Found it. It was a small amplifier for an iPod/mp3 player in the garage. The switching powersupply was generating the noise. Put a mix 31 toroid on both the AC side and DC side and now no noise. I'm just amazed at how well these 2" toroid work. Thanks, -J

oops, was looking at the wrong side of the decimal point :). Thanks Gary. It does appear to be coming in on the feedline because when I take an AM radio near the coax, I get noise.

Folks, Thanks on the other threads the suggestions for identifying and eliminating various RFI across various HF bands. I've significantly reduced my noise, especially with the use of mix 31 and mix 43 toroid chokes around problematic cables. Some really noisy switchers, I've replaced, etc...

For HF correct? But what about VHF/UHF?

Folks, On another thread, we discussed the value of toroid chokes for HF to reduce noise and to eliminate common mode currents. Especially for low band and HF using a mix 31 and mix 43, I noticed a HUGE improvement with noise. What about for VHF/UHF? Do any of you use a choke on any of your...

Power supply for the radio is not the issue. I can turn it off at will and run on the AGM battery. I turned the service MAIN 200Amp breaker off...and the noise goes away. If I turn off circuit by circuit, I drop about 1 S unit in noise, but I don't see a 'specific' circuit that is causing the...

Sure, but when I turn off the mains I go from S3 to nothing on the meter on 80meters. So I'm getting some noise from the AC power lines.

Disconnecting my antennas and I have NO NOISE at all. But the noise is indeed traveling through the house wiring because when I shut the mains off I have no noise. I run my rig off an AGM battery that uses a West Mountain Radio PWRgate to charge it...thus able to run completely on battery power.

So, I got some significant improvement today. I'm using Anderson Pole connectors and a multi-pole junction to feed the 3 radios off the same power feed. I don't run TX on all 3 radios at the same time, so we never overload the power. At any rate, the HF radio I had 2 toroid chokes wound on the...

I would think that the stainless steel cover plate is possibly creating a ground loop as we're bonded there...and then outside on the actual ground plate. Tomorrow, I'll dismantle the cover plate and test again to see if it makes a difference. -J

Folks, I'm scratching my head here and maybe you can help me out. I noticed today that I dropped by noise by at least S3 on the meter for 80/40meters by disconnecting the other 2 radios (VHF & UHF) that are connected to the same face plate/cover plate on the wall. See the attached picture. Its...

I just got one last month. I love it. I love the waterfall display and the interface is really intuitive. HMO has it during the holidays has it for $1080 and there is an ICOM mail-in rebate for $100. So you can get it for $980.