Re: Test equipment recommendations

Robert D. Bowers

That sounds interesting, and would be a worthwhile thing to have (even for someone new, if the software is relatively easy to use and understand).  I'm used to (in my head) "stitching together" the results from my dongle via GQRX, but having software to do it would be great!  (I picked up a broken sweep generator and fixed it, so I have that capability to a degree already, but at the same time that could help in some instances!)

Thanks for bringing that up!

On 5/18/20 11:37 AM, Scott McDonald via wrote:
Given the modeling comments I may regret suggesting this, but as lots of folks have some of the less expensive SDRs, the free software that stitches multiple frequency ranges together to perform as a spectrum analyzer is a pretty cool piece of test kit.

A bit of learning required, but being able to look at the spectrum from your transmitter, or the output of a mixer module, really can speed along learning radio.  Much more intuitive than a scope for RF stuff to me.

I'm most familiar with the free software available for the RSP series SDRs, and have used that with a cheapie noise generator for lots of filter analysis, and am very happy with it.  I believe there is similar software available for dongles as well.  Slower than a real spectrum analyzer for sure, and often some bugs and spurs, but pretty amazing for the price of a free download.

Worth a thought if you already have a cheapie SDR.  

I would NOT do it with a more expensive SDR unless you are darn careful tho :)

Cheers, Scott ka9p

-----Original Message-----
From: Robert D. Bowers <n4fbz@...>
Sent: Mon, May 18, 2020 9:41 am
Subject: Re: [BITX20] Test equipment recommendations

You talk about a steep learning curve for the NanoVNA and then suggest MODELING SOFTWARE?  You do know that doesn't make sense - it could overwhelm someone in a hurry?

Let a new ham learn what they want to learn and when they're ready to learn - in order to pass the test (unless it's really been watered down even more since I got my Extra) they have to have some understanding of the basics already.  You have to build on a foundation - not start erecting the superstructure while the foundation is still being poured!

I'd suggest rather than modeling software, using the ARRL Antenna book or something similar.  That's appropriate not only for someone new to radio, but also useful even for experienced hams.  It also helps to lay a good foundation that can be built on.

Modeling can come later - at their own pace and if they choose.  (The VNA also may be a bit much, although the more a learns, the more valuable such a tool becomes.  That's why a directional wattmeter/SWR bridge is suggested.  Start simple and build up.)

On 5/18/20 9:38 AM, flatpickn via wrote:
If your interest aligns with this:
The NanoVNA is a nice piece of equipment for not a lot of money. I have an H model.
It does have a steep learning curve which would be true of any VNA.
Build yourself a wire antenna. Make it cheap, use speaker wire from the hardware store. Download the free copy of Eznec and model the antenna in it. Use the Nano to tune it and compare it to the model.
When your done, you'd have a good fundamental  understanding of antennas, a beginning knowledge of antenna analysis,  and you'll know the vna well enough to tackle other vna work like evaluating baluns and circuit impedences.
There's plenty of resources on the internet to help you figure it out.

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