HFU HF Underground

Technical Topics => Equipment => Topic started by: Stretchyman on February 15, 2018, 1836 UTC

Title: Simple (Auto) SWR/PWR meter
Post by: Stretchyman on February 15, 2018, 1836 UTC

Def worth a mention...

Got one to recommend to purchases of my TX's and was most interested to see the response supposedly worked down to 1.6MHz.

I also sell a 3W carrier MW TX and was hoping it worked as low down as 1.4MHz, well it does giving the correct SWR & power readings.

Normal (CB type) SWR meters haven't got enough sensitivity to work at low frequencies without transmittting 20W or so (have tried).

So this device is ideal and doesn't need calibrating, just plug in-line and Transmit thru' it, Simples...


                                                                           Digital Power & SWR Meter RED DOT 1.6~60 mhz 2017A 199W


Str.

Title: Re: Simple (Auto) SWR/PWR meter
Post by: Pigmeat on February 16, 2018, 0321 UTC

What's the lowest power level they'll measure? I could see the Ham Qrp'er's going nuts for something that measures from microwatts up.

Title: Re: Simple (Auto) SWR/PWR meter
Post by: Stretchyman on February 16, 2018, 0936 UTC

Micro what's!!

Why be concerned with VSWR at those power levels?

It's fine with 3W at 1.5MHz, that does it for me.

For piddle power just use a resistive bridge and amplify the results, so simple, that's why no one is making them I guess.

Title: Re: Simple (Auto) SWR/PWR meter
Post by: Pigmeat on February 16, 2018, 2156 UTC

You're dealing with hams who want accuracy at the click of a button. None of that math stuff for them. They used to use the test strips from packs of Energizer batteries to guesstimate those micro power levels until the Energizer folks discontinued the strips.

Title: Re: Simple (Auto) SWR/PWR meter
Post by: ThaDood on February 17, 2018, 1721 UTC

    I know that AM Part #15'ers would love a micro power / VSWR meter for the radiating measurements of 100mW, and less. And even the Carrier-Current measurement of 30W, and less, is useful.  There's the Greek dude at PLL.gr with this meter,   http://www.pll.gr/product?pid=PWR-SWR-Meter   , which I want to get. However, to measure the really low power on the MW FREQ's, what's out there? Yeah, no doubt that you could make one, and even modify a CB unit to go there, but then calibrate it right. Why have this at flea-power? Efficiency. Why put out, when you find later that you can't get out?

Title: Re: Simple (Auto) SWR/PWR meter
Post by: Clutter Free on February 23, 2018, 1310 UTC

Hi Stretchyman.

Cheers for this. Have you tested it any lower in frequency? say 1125Khz  ;)

Title: Re: Simple (Auto) SWR/PWR meter
Post by: Stretchyman on February 23, 2018, 1656 UTC

No, just down to 1.4.

It will be fine I'm sure.

Str.