开云体育

?Hi Just to add to Martin’s comments.. G3TZQ chart is very helpful.( ie the Bible on cm chokes.) But was primarily designed for common mode chokes on Tx cables going to antennas. They are the

Ideally, you need to tailor the core material and number of turns to work at the most problematic frequency. Just one pass of a cable through a single small clip-on core will not do much at short

You night be better off with mix 31.. Everett N4CY Sent from the all new AOL app for iOS

Thanks , yes? only have a ferrite bead because the cable is too short between the Pc and the speakers. I will try with a big toroid 43 or 71 ferrite material. I will use longer wires. I hope this

Class D and E are switchers and to be avoided. I'm guessing the RFI you are experiencing is conducted on the audio cables from the PC, itself. Once energy is present on the cables, they become

I have only a SDR a Winradio Excalibur with a Wellbrook antenna, it works superb but my main problem are the PC speakers, Trust speakers, it has a class A amplifier and radiates a lot s of RFI , can

Hi Use the rx in antenna port for loop..its an icom so should have one. (If its txing into loop you worried about.) Simon g0zen

Thank you everyone who has helped with my question for these great ideas. I'm pretty sure I understand how I need to proceed now. The biggest problem with the Icom 737 is the pesky transmit button

Add a PIN limiter diode across the input terminals. Why a PIN diode and not an ordinary small signal diode like 1N4148? The former's longer carrier lifetime prevents the diode from "following" the RF

Looked up the amp. The two transistors seem to be marked as "1A" which are generic 2N3904 surface mounts. They would be National Semi process process 23 devices which have a 2db NF above 100Khz. One

Found this on another group and thought it might interest someone here, but not for the budget minded: https://www.netsandmore.com/products/fishing-accessories/fiberglass-hoops

Hi Use ptt out ( used to switch amp to tx)to control a little relay in line with rx coax. If the relay goes after bias T ( loop side) it will also shut off power to loop preamp. The relay crt is

Hi Tom, it's an Icom IC-737 73 Adam

What rig are you using?

Hi, I have made an indoor active broadband loop for HFusing the LAMB-1B amp board from Casarain. Having now got back into amateur radio I want to know if there is anything I can build on the lead to

Yes indeed, it's gone. Please take this: http://web.archive.org/web/20240416151211/https://www.reeve.com/Documents/Articles%20Papers/Reeve_AntennaSystemGroundingRequirements.pdf regards Fred

Hi Fred Link is dead... 73 John

We have to distinguish between functional ground/earth, which is needed for the proper functioning of a device and the mandatory protection earth and equipotential bonding. The latter dos not care

Yep! Computers are major RFI generators! Dave - W?LEV [email protected]> wrote: -- *Dave -

Dave, I eliminated a good part of EMI from my computer by grounding all of my equipment to a central point on the computer. Additionally, using the original mini whip it is recommended to ground the