You don't want to be connecting a VNA to your rig, ever, only to an aerial without the rig. Nearly all SWR meters measure power too. The ones for CB use a strip line sampler, so above 27 MHz they take too much signal (though you can cut it in 1/2 for 50 MHz or use about 1/3rd for 144 MHz. They can be adapted to measure power only on any band. The HF SWR meters use a toriod transformer with the signal using 1 turn. They may not always be good for 160m or 10m. The CB type meters are OK on 10m, and may be OK 21 MHz to 29 MHz.

If you are measuring power to a dummy load you don't need the SWR circuitry, simply a resistor divider and pair of 1N60 diodes as a peak detector. That then needs calibrated.

An Ardunio or other mpu is only needed for an automatic SWR meter where you don't have to set forward power reference level. All simple SWR meters will also measure forward power as they need that for the cal setting and sensitivity knob, though some may have poor calibration and many only work over a particular range. There were expensive easily damaged wideband HP power meters that could measure almost any frequency and waveform as they used a thermistor. The really expensive Bird meters are more robust and much cheaper!

No cheap VNA is any use to measure power. Mostly the signal generator is no use for anything other than built-in measurements on cheap ones.

One old method was to use two lamps behind a screen that were approximately 50 Ohm at the desired power (tungsten filament lamps can vary 1:10 between cold and hot). Then you connected one to device under test and the other to a PSU. You adjusted them the same appearance/brightness and then the DC PSU readings are your power. Still can be handy above 1 GHz as a rough check.

You can use a cheap CB meter on 28 MHz on the FT817 with a dummy load, if you have a method to calibrate / check it (most have gain pots). That then tells you the FT817 and its inbuilt metering is working (or not), Then assume the FT817 metering is a rough guide. A quality 100 MHz scope may be good enough for HF to see peak to peak on a 50 Ohms dummy load and then you can calculate the power = (peak to peak / 2.828a) squared / 50

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A year ago I found one of the appropriate AOR-branded 300Hz Collins mechanical filters on the eBay Japan site for the ? equivalent of about $100. The seller, a Tokyo based AOR dealer, had just one filter, so I bought his last one. It arrived in an AOR box a week after placing the order.

My original query was in the FT-818 group but should be accessible here:

/g/Yaesu-FT-818/topic/chinese_made_cy122_filter/100249352

I bought one of these filters and put it in my FT-818. It’s the 2.7k version from eBay.?

see

I asked the same question about these way back before buying and there was a fascinating thread of responses. It might be worth reading through the thread if it can be located with a search.

I’m not sure it made a significant difference but the radio definitely sounds a little quieter. During a Sunday night QRP SSB Net, I asked the 2 Net controllers located far apart in SC and IA to give me an audio report for my transmission when the filter was on and off. Both reported better audio with the filter on.

For ~ $100, I felt it made a slight improvement, and I was not going to spend the big $$$ on the mechanical one, which was about half what I paid for the radio.

Lots of good ways to measure QRP power.? I like to sweep a load resistor at the desired frequency to make sure it's a pure 50 ohms resistive and then I use a scope with a carefully compensated probe.? With a nice sine wave, RMS power is a simple calculation.? Another way is to put a 50 ohm load resistor in a thermally insulated box, poke a small hole in the side of the box and measure the temp rise of the resistor with an IR temp gun.? Calibrate the measurement with a DC current thru the resistor.? Again, the resistor has to be pure with little or no reactance at the measurement frequency.? And paint the resistor black to get the emissivity near one.

Dave, kx3dx

All Hams, IMHO, should have SWR meters, no matter the bands of interest.? Is essential for antenna work.

It's the 21st century, most hams should have a VNA by now ;-)

And they can display swaaaar too.

All for the price of a Mc Donalds Happy Meal these days,? far more versatile
and educational than a swaaaaar meter on it's own.

As for common power meters, well the problem with those is that they
are additive types unless you use something like a Bird with a frequency
selective slug, otherwise the power readings can be innacurate.

Additive types relying upon simple diode detectors for example will
not be much use of the TX has spurious emissions they get added
to the reading, as do harmonics.

For example 1st, 3rd and 5th harmonics can add to the readings.

But in fairness if you're just looking to read the power of something
like a properly functional FT817 where filtering is working correctly
and you just wish to customise the power settings or check supply
voltage vs power output then a bog standard power meter is good enough.

But no good for golden screwdrivered rigs, homebrew and malfunctioning
PA's.

You might need a speccy analyzer for that too, but they are cheap now.

Just give up eating donuts for a month and you can afford something
like a TinySA Ultra (and you'll be healthier too).

All sorted.

73 de Andy G0FTD

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Ron,

On Thursday, June 27 2024, 15:25:37, Ken N2VIP via groups.io wrote:

Were Yaesu/Collins filters EVER $100 options?

there are many options, perhaps not as evident as making a google search and picking the firsts results, but original collins filters of same characteristics are still available new as AOR parts. Mounting them on an aftermarket board puts it int he $100 range or slightly above it.

Just search the archives. :)

--
Americans detest all lies except lies spoken in public or printed lies.
--- Edgar Watson Howe

I had forgotten that QRPGuys makes a nice little power meter accessory. ? for $40.? It was very easy to put together and includes a QRP dummy load on the board.? I think I built it in one night.? I have it sitting on a shelf under my station monitor.? It is battery operated so I only connect it when I need to verify power and my other meters.? It is a very handy device.? You need to wind the transformer but that is the hardest part of the kit.? It is very small and there is a 3D printed box that you can make too.? They use PayPal as an interface for payment and shipping.? Please see their for details.
--
Al Skierkiewicz
WB9UVJ

Ken

I had no idea that Google would find that InRad sale !

LOL

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So the answer is "yes, they were once under $100" albeit as close out deals to clear out older filters for what are now 40-50 year-old radios...

On 2024.06.25 06:37, Michael Newbury wrote:

A swr meter aint gonna give you a power reading is it, its gonna give
you a swr reading, unless you get something like a cross needle
power/swr meter or the like, as for the mulitmeter, err i dont think
so.
Mick SA4MDN

Hi Mick,

Three of my bridges do.

73, John
--
John D Erskine
VE7MHI VA7OTC
CN88hk VA7RCN
Victoria, B.C.

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Excuse me for butting in but I think what you may be looking for was made by W4RT. He is no longer in business. I have two FT-817’s that have his board in them. The board allows you to have a CW and SSB filter installed. W4RT used Collins filters on his board. These are very to find.

Sotabeams makes a DSP filter board, I believe that is what you are thinking of.

73

Ken

See the Inrad post below and weep

Closeout pricing on roofing filter kits TS-850, TS-870, TS-930, TS-950, IC-756Pro, IC-756ProII, IC-756ProIII, IC-781

Closeout pricing while supplies last on roofing filter kits for TS-850, TS-870, TS-930, TS-950, IC-756Pro, IC-756ProII, IC-756ProIII, IC-781 transceivers. $69 plus shipping. At left click on Product by Radio under 'Categories' then enter either Icom or Kenwood to bring up the individual radio models list.

Closeout pricing on certain Heathkit, Icom, Kenwood, Yaesu filters for 1970-80's-era transceivers

A few models of INRAD filters for 1970's-80's era Heathkit, Icom, and Yaesu transceivers are now discontinued and remaining inventory is now sale priced at $40 each vs. usual retail of $118 to $174. For Heathkit: #2708 1.8 kHz SSB filter 3395 kHz I-F. For Icom: #113 2.1 kHz SSB filter for IC271, IC471, IC701, IC720/IC720A, IC1271. #320 1.8 kHz SSB for many Icom models. #322 1.8 kHz for many Icom models. For Yaesu FT-102 and FT-650: #1201.2 250 Hz CW filter, #1202.2 400 Hz CW filter. For Yaesu FT-102, FT757GX, FT767GX: #1209.1 2.1 kHz SSB filter. For Yaesu FT-101, FR-101: #2003 500 Hz filter, #2008 1.8 kHz filter. Kenwood TS-930/TS-930S roofing filter modification kit reg. $175, now $59. Quantities are limited. Type the model number into the search box at upper left to be taken to order pages.

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Wasn't there a 3rd-party DSP board option at one time? While maybe not as good as OEM filters, they could be a reasonable option.