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dec·i·bel noun a unit used to measure the intensity of a sound or the power level of an electrical signal by comparing it with a given level on a logarithmic scale. db is what I would call

I would agree with this. There was a paper in an IEEE journal saying that the term return loss is used badly. As far as the author was concerned, a return loss of > 0 dB implied a gain - negative

Here is the take away... The minute you say Return loss, everyone knows what it means... 73, and thanks, Dave (NK7Z) https://www.nk7z.net ARRL Volunteer Examiner ARRL Technical Specialist, RFI ARRL

TU all for such wonderful comments, all helping me to visualize the concept of RETURN measurement. I think when we add the word return LOSS it bothers me. A double-negative is always problematic: so

I would argue that if you WRITE DOWN "RETURN LOSS -26dB" I would think of that as a double-negative. If it's a loss, as with finances, it's negative. A negative loss is a positive (double-negative!)

Just my 2 cents ... I agree that it is a convention ... but to me it still is a "historical error" (not sure, but I think the formula with the minus sign was introduced by HP) . It is generating more

Many thanks Roger, for your answer ... Just pointing-out to the series resonant circuit (at very input before the semi-rigid line) : 47 ohm - 330nH - 220pF ! I cannot understand what is its purpose

Peter, it helps to think of the active devices, the PA power transistors, as horribly non-linear devices. The base-emitter junction is a forward biased diode, whose small-signal parameters vary over

Just in case, it's not a concern about "space hardware" per se, it's the particles and coating from the sheet material the pink poly bags are made from getting into the electronics and causing

I might use one of the anti static envelopes I have as an added feature. I can see for what JPL is involved with any particle shedding causing issues. But with my experience with the pink foam in

You've received many good replies, but I can't help to contribute mine as well, so: Quote: " So the FORWARD voltage is always positive and the RETURN signal is attenuated.." But if all we measure is

On 6/28/21 8:24 AM, Maynard Wright, P. E., W6PAP wrote: > Carey, > > You are exactly right.? Terms such as "return loss," "reflection loss," "reflection coefficient," "SWR," etc. all have precise

When you apply bias to the transistors Q1 and Q2 the input impedance looking into the base of the transistors changes. This affects the overall input impedance of the network (including any observed

Art, if you're using defuse to update the software, read my post several messages back.? Defuse uses confusing terms. Upload means to copy from the device to the PC.? Read my post and install the

We had a topic on this subject a few months ago. I posted a link to a paper by an IEEE editor on the "Definition and Misuse of Return Loss" which details the history and why it is a positive number.

Hi William ... of course the "squared BIAS" I Drawn is just the one made with the BY1-1F ... there is no any other Bias ... I was asking WHY the INPUT Resonance changed as soon as I apply Power-Supply

Aside: not sure why you are biasing the input, looks like the transistors are already biased on thru BYI-1F, and the input is capacitively coupled. At the very least the B-E junction of a transistor

Carey, You are exactly right.? Terms such as "return loss," "reflection loss," "reflection coefficient," "SWR," etc. all have precise meanings that are very important.? Many of them are defined in

I reloaded thee software and it shows the device. I uploaded the new firmware and the program shows device 00 updated and the screen shot is like the one you provided. When I check the firmware

I'm not convinced that tells you anything useful, unless one is known to be good. A lot of these VNAs are copying code from another, so I would not trust that. The classical verification/transfer