QRM Eliminator (Why you need to connect a PTT cable)

Рет қаралды 4,680

11 ай бұрын

#hamradio #noise
WARNING! Not sending a PTT signal to the QRM Eliminator allows your RF output power to get into the receiver circuitry of the device, and that could cause permanent damage.
The QRM Eliminator, and other phase cancellation type noise elimination devices, need to be signaled when the transceiver is outputting RF.
There is an RCA female connection on the back of the device, where we must connect an RCA cable that enables the bypass relay inside the device, by completing the path to its circuit ground. It will require a PTT signal from the radio or you can connect a foot-switch, such as the Heil FS-2. The PTT relay bypasses the sensitive receive circuitry and routes the RF power safely to the main antenna connection.
At the end of this video, you will be able to see a listing of some of the supporters of this channel who made this video possible. These are people who have supported the channel via Patreon membership, as what I call long-haulers. Long-haulers have supported the channel on a long-term basis. There are 4 levels of Patreon membership, including S5 (Associate), S7 (Executive), S9 (VIP), and S9+ (VIP+). S9+ (VIP+) denotes an S9 (VIP) member who voluntarily chooses to give over and above the amount for S9 (VIP) membership. They help me continue to produce videos even though most people do not contribute toward the cost of my mission. Without their support, I cannot bring my viewers uncensored content.
I hope you enjoy this video and find it helpful. If you find my channel informative and entertaining, I hope you will consider joining my support group by clicking on: www.patreon.com/N4HNH There are 3 levels of support, including exclusive content. Visibility of premium content is determined by the level of membership you choose. The higher the membership level, the more content you have access to. VIP members are invited to participate in periodic Zoom meetings.
Most videos are visible to the Patreon team members long before they are released for public viewing. Some videos are never released for public viewing. Yearly S7 (Executive) and S9 (VIP) members have access to the menu optimizations PDFs I’ve written for the FT-891, FT-991A, FTdx5000MP, FTdx101D/MP, FTdx10, and FT-710 AESS. Yearly S7 (Executive) members can receive one menu optimizations PDF while yearly S9 (VIP) members can receive multiple menu optimizations documents, plus my FT8 configuration guide for either the FTdx10 or the FT-710 AESS. Future radios might be added. The documents are copyrighted. They shall not be divulged to anyone else without written permission from Doug McAlexander, callsign N4HNH.
N4HNH Radio has a Web site where you can purchase T-shirts with some of the sayings you might hear in the videos. Some of the more prominent videos are featured there as well as a page geared toward ham radio training. Go to: www.n4hnhradio.com
Another great way to help support this channel is to click like and subscribe.
73, de N4HNH

Пікірлер: 12

@volosguard 9 ай бұрын

Thanks for this great video! I own Yaesu FT-710 and I wonder where should i connect the PTT cable (the one with RCA connector on the one side and naked on the other). I suppose on the Tuner/Linear 8 pin connection soldering TX GRD and GRD pin to a 8 pin mini din connector, but not sure....

@n4hnhradio 9 ай бұрын

If you don’t use an amplifier or an antenna tuner, the 8-pin Tuner/Linear connector can be used. You need ground and PTT. I use a Heil FS-2 footswitch, so I don’t have to tie up the Tuner/Linear connector.

@sm6yec 4 ай бұрын

Can you use VOX whit this setup ?

@n4hnhradio 4 ай бұрын

Not very well.

@mikewalsh511 5 ай бұрын

What path does the RF take inside the QRM eliminator when the PTT isn't triggered? How does it not blow up?

@n4hnhradio 5 ай бұрын

It will blow up eventually. The RF doesn’t get diverted away from the receiver circuit if you don’t provide a PTT connection. That is why I made this video. I damaged mine to make this video.

@Nick_G7IZR 11 ай бұрын

Try RM Noise, the AI noise reduction. Works brilliantly.

@n4hnhradio 11 ай бұрын

Yes, I’ve heard the RM Noise software demonstration. Not bad but I still hear a remnant of the noise, and the received audio is adversely affected. Phase cancelling the noise before it ever reaches the radio is still the most effective approach. As I show throughout my videos, it is best to attack noise in the front end of the receiver first, before it even gets to the second IF, or SDR stage, and especially before the DSP stage. But, it’s even better, to stop it before it enters the radio, like the phase cancellation devices do.

@kd4exy 11 ай бұрын

The Heil fs2 has been disconnected. A new fs3 is only one they have

@n4hnhradio 11 ай бұрын

The FS-3 only has one switch/cable. It won’t work for the QRM Eliminator. I already made a video about the FS-3.

@CBRadioWayBack10-4 8 ай бұрын

who cares, it's a video about the QRM eliminator.

@n4hnhradio 8 ай бұрын

The Heil FS-2 is the easiest way to provide the required PTT signal to the QRM Eliminator. I spoke about it in the video. That’s why @kd4exy mentioned that the FS-2 has been discontinued. In fact, it was only discontinued a few months ago. I’m sure @kd4exy meant to type “discontinued”, not “disconnected.” Some newer transceivers do not have a TX GND connection that provides the dry contact for the PTT signal via an RCA cable. A special (usually 8 or 10 pin DIN) cable must be made and connected to the Tuner or Linear port, which prevents those ports from being used for their intended purpose. It’s especially bothersome with transceivers like the FT-710, which has one port that you must choose in the menu to either be for keying a linear amplifier or operating an antenna matching unit.