Field Strength Meter

RE: Field Strength Meter

shabaz — Tue, 21 Jan 2020 05:55:48 GMT

Hi Mike,

It's great to see this RF project : ) The results look good, especially considering the desire to keep it low-cost with the diode detector.

If you ever wanted to upgrade that part of the design, there's some chips (more expensive than the diodes unfortunately) that have very few connections, and are all-on-one diode detectors and log-output amplifier, with a voltage output that could go into the Arduino as you have it, or into any multimeter/panel meter. The AD8307 is quite popular, since it is in a easy-to-solder SOIC-8 package, and needs hardly any components. It's expensive though : ( Newark/Farnell has an alternative, MAX2014 but in a harder to solder package : ( In some ways it is better, due to higher frequency span, but the AD chip has a greater power measurement range.

eBay always seemingly has plenty of AD8307 that are cheap, but it is a extremely common fake chip.. I got 20, all were fake (top sanded down and re-marked) so if it looks like a bargain for that chip, it probably isn't : )

There's also a LT5507 chip, again hand-solderable (but not as easy as the AD8307 which is very easy to hand-solder). However it is a very basic chip, since it doesn't cover as large a power range and not very linear. It is cheap though. Photo below is of my crude LTC5507 meter. I've purchased a AD8307 however, since the LTC.. chip wasn't meeting my needs.

[View:/resized-image/__size/620x465/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-eedc1058-9339-44e3-92c7-6e515be4c402/2043.contentimage_5F00_192301.jpg:620:465]

RE: Field Strength Meter

jw0752 — Tue, 03 Dec 2019 16:14:44 GMT

Hi Mike,

Excellent project. I like how you explored various options and I like how you incorporated the HF meter into the build. Where do you think the inconsistencies are entering the system?

John

RE: Field Strength Meter

rsjawale24 — Mon, 02 Dec 2019 16:52:32 GMT

Nice design. However, as you said it takes lots of efforts to get constant results. Why not go for a RF power detector IC? That way you can explore the higher frequency ranges (in GHz) as well [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-eedc1058-9339-44e3-92c7-6e515be4c402/contentimage_5F00_1.png:16:16]

RE: Field Strength Meter

genebren — Sun, 01 Dec 2019 21:56:16 GMT

Nice build! Building tools is frustrating and rewarding. Thanks for sharing your project.