#292 

Explained very well, I am construcing the same Z match from scratch for a start without the bridge good results so far.

I like the caliper lead bending technique. I’ll have to try that.

Another first rate video. Holds my attention right to the end even though I'm not going to build it. Numerous good tips too. +1.

Thanks for the excellent video. I especially liked the theory portion. (And I seldom say that.)

I have one of their antenna circuits and it has a very similar circuit to this tuner. The instructions are great and it's easy to build.

Cool little tuner Alan! I'll have to get one. I wonder if anyone 3-D prints a case for this? Thanks for walking us through the circuit and explaining each sections function. I love it when you do that as I learn a lot! 73!

Nice kit build Alan...I love PC board case construction, especially when you consider the skyrocketing cost of enclosures nowadays (hint: you can do a lot with the old PC switch boxes and metal hard drive enclosures which can usually be had very inexpensively). 73 - Dino KL0S

Very - Very well done video and description of the circuit. In the middle of building a different unit and actually this one looks like it would have been a better choice....

Well, saved me some $$ - from their site - Fall recharge… QRPGuys will not be shipping product from now and until most of October. We will only be providing e-mail support, and answering inquiries.

@w2aew I have a question... The conventional ratio for matching a transmitter output to an untuned end-fed wire is 3:1 winding ratio to produce a 9:1 (50 Ohms to 450 Ohms) impedance transformation, yet the winding ratio for this transformer is 16:12, which is going the wrong way. Even if I'm misunderstanding the circuit and it's really a double 8:12, that's still only 1.5: 1 winding ratio for a Z match of 2.25:1. The low impedance side is 16:6, which seems equally wrong. What am I missing here? Is there some phenomenon that magically makes the primary a 50 Ohm load to the transmitter? Or does it rely on transforming the impedance of the secondary circuit (transformer secondary and antenna) to generate that effective impedance? Backing up, and sharing what I think I know about this... C3 and T1 primary form a parallel resonant LC circuit, which has its highest impedance (and therefore voltage into the transformer primary) at resonance. Conversely, C2 and T1 form a series resonant LC circuit which has minimum impedance at resonance - again, transferring the maximum energy to the transformer. All that makes total sense... but the ratios? I'm scratching my head.

i like this tuner, but am quite happy with the much simpler sota tuner (and the older BLT+) because of the enclosures... what's really good about your video is the circuit explanation, especially about the Tayloe indicator - so tks!

Could anyone explain the significance of the center tap on the primary? All my Google results only deal with a tap on the secondary. Thanks

Great video. Just built one of these for use with the Icom 705 I have on order. Really like how you walked through the schematic, very helpful to a novice like me.

It doesnt have swr meter, Its an swr indicator more then anything else. Good Video :)

Thanks for the video as I am looking at getting one ! Has anyone fabricated a case or box for it?

Hi Alan! Would it be possible that you put together a course on circuit design from basics up to somewhere you are right now? I have been looking for something like this for a while. What you're doing here could never be learned from reading books, even if you read a million books. I find your language and style of teaching invaluable and I'm already learning a lot from your videos. I know that you're very generous but if you asked me to pay for that course, I certainly would, most probably many people would. Would you please think about it? Thank you!

Thanks for sharing! Cheers, Dave - KU9L

Very neat video. I'm posting it on my ham radio fb group. Excellent explanation of the Z-match design. But what's the "Heat it inside" sticker on top of your FT-817? Curious.

Love the written instructions. Reminds me of the old Heathkit kits.

10:59 - With it in "tune" mode why will the radio never see _"more than 2:1 SWR"_ ?

Hot dog, # 1 view , on stand by for big blow coming soon. Dave, W4GSM

I just built this tuner with the aid of your video. Works great with my 20 meter MFJ cub. Thanks for such an informative video,de KD3D.

what a great little unit, one day I'll get into qrp opps

Thanks for this and your review of the EM-2. Both might benefit from larger knobs. I opted for the ZM-2, since I wanted a case. I like QRP Guys gear, but planning to use them outdoors, I need something with a case.

Pretty cool kit. Thanks Alan.

Thanks for posting this. The one I ordered came in a day early. Im looking forward to building it. The only part im concerned about is getting the feont board mounted right.

I built one , but couldn’t get it to work correctly. I measured the ohms in the 3 51 ohm resistors. Found one to be 51 ohms, but the other two only measured around 25 ohms each. Contacted the vendor for replacements. Will see what happens after I get them. Great video and explanation of the circuit.

This is a good overview and the tuner is about half the price of the similar MFJ QRP tuner which lacks the SWR indicator.

Who in the heck would give this a thumbs down? Very helpful video, thx!

HI, Do you have modification, which will cover 80m band?

What length of wire would be best for 40-10 meters?

Any reason to use/make an auto-transformer instead of just two windings on a regular transformer? - 9:35 For the amount of wire required it would seem simpler and easier to use two windings.

I was sent a .01 instead of a .1 for C1..Do you think it is OK to use it or should I get the.1?

QRP Guys make good stuff. They are off thru October so no ordering at the moment

The lead bending trick is awesome. Neat, simple SWR indicator circuit. I like it! Thanks for sharing.

Thank you for explaining the tuning circuit. I have a couple of their kits, and a 4S tuner as well. This seems to be a common circuit found in all of the kits I’ve assembled so far.

Shame he didn't ask the PCB fab to leave off the PCB id code off the board.

hook it up to a vna

nice video, well presented!

Hi There, greeting from UK! (Apart from the 80m band) How does this kit compare with the Emtech one in terms of ease of build and components quality? Thanks for sharing

just finished building mine. Thanks Alan.

Hello! Very interesting and educative video. I'm thinking of buying one for myself. I got one question though... Can I use a "Loop" wire with this tuner? Thank you!

Can bigger caps thicker wire be used and a 240 torroid be used to make a 100watt version using the same schematic?.

I used to love QRP on field day night shifts in the Arizona desert. June is always so hot here

This video was worth it just for how you bent the LED.

If I wanted to use a single wire with this tuner, would it be a resonant or nonresonant length?. Im not sure what a z match tuner is for. Thanks for your help. KG7CQG

Unfortunately, the expensive postage stops me from buying anything from them! Which is a shame because the stuff they make is cool!

Excellent project

Quick question. Can you tune for max noise then key up and be even closer?

very nice job and kit!!

Thanks Alan for another great video!

Is This a tuner for any mobile radio use in cars? eg. Motorola CM series.

Hi, nice vid, I have a question. Where can I buy this kit? :)

Hey, do you think it would be possible to replace the LED SWR indicator with a connector that went to a MicroVNA instead?

What are some good projects as an intro to RF electronics? I find the "black magic voodoo" to be intriguing, but it would be nice to test the waters before taking the (rather expensive) plunge.

Will this tune random length whip antenna for 11m?

Good... $ ?

This may be a question I should just Google, but I'll throw it out there anyway - is there an assembled version of this, or a commercial product that does that same thing? I am not that confident in my soldering ability.

Thank You

Nice

Perfect

I'm looking for a QRP SWR and power meter. It is mainly for a WSPR transmitter so max power at full scale of maybe 0.5W. Any recommendations? I would like to leave it in circuit continuously unlike this SWR indicator.

Two questions. You mentioned that when the LED is extinguished, the transceiver will see a perfect 50 ohm load. That doesn't correct the antennas impedance, correct? The tuner is there to protect the transceiver only?