开云体育

Hi Paul Amazon sell the kit, try this:

And the exact noise bandwidth varies from the nominal IF filter 3dB bandwidths, and with the shape of the filter.? You can watch the instrument (higher-end one anyway) making these measurements when

Having trouble finding a source for the kit. All seem to be already assembled, Any know of a kit source? 73 Paul w2eck

Dan, The transformer in my transceivers has been wound for a 9V input. I use a INIU 2000 mah Power Bank in combination with the DSD TECH Type C PD ?to DC power cable at 9V output. The cable comes

Yes I was discussing the part soldered to the PCB. But, to be honest I am now at a loss as to the problem? I removed the socket from the printed circuit board and retested it with nothing connected to

I restored the original connections in my QMX+ so that the LPFs are once again in the RX path. It made things generally worse, by a lot in some cases. The artefacts were due to the QLG3 which I have

I posted a short video of how the QMX+compares with the KX2 and FT-891 in terms of receiver sensitivity on 20m: https://ae5x.blogspot.com/2024/12/receiver-sensitivity-of-qrp-labs-qmx-is.html On other

I'm not surprised at all by this difference, especially noting that these tested values are from QMX/QMX+ units that were sent to Jeff because the original kit assembler did not have the skill to

Note that FT8 vs CW cs SSB bandwidth MDS is a matter of specification. When specifying a minimum discernible signal it is only relevant when specified alongside the noise bandwidth. Or in other words

Hi Allison, you are right of course. A very good and simple test is connecting an antenna instead of a D.L. and hear the noise (not the signal). The FT-8 bandwidth alone adds 10dB (50Hz from 500Hz

Tony, Those numbers might degrade by a db or two for the filters. Bigger issue is ambient noise and overload. For 10M its ok to good at -126dbm.? For 6M -113dbm is about 13db weaker than my worst

Wouldn't the existing PTT output signal do for this?? receive != transmit; Chris, G5CTH

The way that the generator is loaded is easily solved using a 10 db pad between the generator and the rx. For MDS I use a Gertsch/Signer FM10C as that or my Measurements 803 both generate accurate

Well, I used my HP 8643A and an HP400E to measure the signal needed to give a 3db rise in the audio in CW mode with a 500Hz bandwidth. But my QMX+ has been modified with a separate RX antenna input

Hi all, following the debate in this thread I did some MDS (Minimum Discernible Signal) subjective/objective measurements my-way. I have used: - QMX+ at +12V - Agilent RF gen and additional 10dB RF

Jeff W1NC: Thank you very much for this test based info.... A 10 dB difference between units though !! Alex

Hi Alex I don't think that would be consistent with my observations. My noise floor rest method involves injection of a signal at about -60dBm from a QRP Labs VFO kit into some 50-ohm attenuators,

There are dozens of options that ham experimenters designed, built and sold as accessories over the years that the 'bigger brands' took years to finally incorporate into their offerings. A few that

Alan G4ZFQ: Agree. Radios,? just like life, are a set of tradeoffs. Some tradeoffs are more important than others. For the QMX+? however,? an outboard ultra? low noise front-end amplifier

If you have the same fault in more than one kit, I can't help but think there's something you may be misunderstanding about the instructions. -- 73, Dan - W2DLC