Hey, thank you so much for the videos you produce. You have a remarkable talent in your ability to explain concepts in such clear and understandable ways. I find that I always look for any videos from you first thing now. 73's and keep those videos coming!

When I need to shorten a ferrite rod I put the rod into a drill chuck tightened just enough and then rotate the rod in an opposing direction to a Dremel fitted with a diamond wheel for a nice even clean cut.

@MIKROWAVE1

4 ай бұрын

Wow that is better than the crack it on the table edge method by far!

Another very interesting and enjoyable video. If you have to do the math, it's easier if you choose a frequency like 1600kHz (actually 1592kHz) where 2pi = 10^7. 3200kHz would also make calculations a bit easier. I remember this from telecoms exams years ago when we used slide-rules and log tables.

@MIKROWAVE1

2 жыл бұрын

I love the old radio shortcuts and rules of thumb. The other trick is using harmonics of the signal generator to set the alignment points on the dial like 1MHz and 2 MHz, rather than retuning.

Always, great video man; bravo.

Having fun with these, both mn and NI ferrites. Made rods 240mm long. Watch out for poor ialectrics. Don't use pvc. Polystyrence best to cover rod in one layer before winding. 73 wa2kbz

@MIKROWAVE1

Жыл бұрын

AhHa a ferritephile. Very nice Karl.

A suggestion for cutting ferrite rods is try a dremel and cutoff wheel it might have less risk breaking the rod with a more controlled cut clean through. And thanks for the well explained video, you've given me good advice for an AM active antenna to compliment my dx radio.

Very very informative..thanks a lot..u almost cleared all doubts regarding ferrite rod

Thanks as always,,, good stuff.

thank you ...basic radio projects are very funy and interesting

An excellent presentation, many thanks.

@MIKROWAVE1

Жыл бұрын

Thanks for watching!

Great fun. Thanks.

Great content! Thanks. For those that have an RF generator and an oscilloscope but no LC meter, there is a PDF from Tektronix called "Capacitance and Inductance Measurements Using an Oscilloscope and a Function Generator".

@sarahhoward9081

4 жыл бұрын

I have been trying to look into this, found one video about it where they don't tell the values of any components they're using. I have a signal gen and oscilloscope. Any idea how this circuit works?

There is always something to learn. Tks Fer gud demo de kv4li

fun stuff. thanks much.

Enjoyed your presentation, looking at your transistor radio schematics I am converting one to 10 MHz (9.5 to 10.2) for wwv try using 10.7 if cans for receiver front end and another transistor to 10.7 if can osc to mixer transistor. you have a new subscriber looking forward and thank you watching your videos.

Thank you for sharing your work. Your videos are excellent. Can you discuss impedance matching to improve volume in headsets or amp input? I don't understand what it means when the detector gets loaded up and volume is reduced. Also can touch on LC circuits about how frequencies are accepted or rejected (tuned) using LC resonance?

Thanks again, Mike. Allot to chew on...I'm going to review the series a few times. I've got a project I'll be working on this week...a wideband untuned active loop antenna. I'll have to wind two xformers on Amidon type 75 binoc cores (have them onhand, and they're the right mix...dumb luck). One for the input of the balanced loop to the unbalanced LNA, and the other from the output of the LNA to the coax. Hope it works out. It's the only antenna option I have in this very restricted community.

@Karl63601

5 жыл бұрын

OOPS...I meant to say type 73 cores.

@conservative599

3 жыл бұрын

Hi Karl, No one explains the technical details of classic radio technology as MW on this outstanding channel! That receiver cost new more than my house! He has collected the best boatanchor radios and Test Equipment short of Dr. Carlson's Lab. For your project, I want to add a link for an English Ham that has picked apart, built and tested most every Active Antenna on the market or homebrewed: MARTIN G8JNJ at www.g8jnj.net/activeantennas.htm

11:00 Could've sworn that Ferrite was the newer technology

@MIKROWAVE1

3 жыл бұрын

Dunno but powdered Iron came first and that was used widely in WW2. Brass was also used but it reduces inductance and adds capacitance, so it is not often seen. Ferrite mixes are all over the place now covering most of the LF and HF spectrum and powdered Iron made a comeback for VHF. See Micrometals Company.

Great video! Thanks for sharing your knowledge. I do have to protest the using the bridge and then pulling up a smart phone running real calc, should have used a slider rule, or an old Friden calc. Just kidding. But at least run it in RPN mode.

@MIKROWAVE1

3 жыл бұрын

AH yes. You are spot on! My wife and I both had slide rules. She was a bio student. I actually had a class in slide rule with one of those giant wooden jobs over the blackboard at SUNY.

nice ! i think maybe a disc cutter would be nice for a good straight edge cut, im experimenting making my own transformer designs so i want to cut out pieces of ferrite for my trnsformer cores ! : )

@MIKROWAVE1

2 ай бұрын

Wow I want one of those.

@tvdylan

2 ай бұрын

@@MIKROWAVE1 mm! Maybe are disc cutter isnt so.important for.your situation. Ive bought some.more ferrite pieces and mannaged to.make.the shape of.transformer i wanted with small ferrite pieces instead of cutting small pieces!

Are sunk there at Rob's that are in good am radios already rap with the right amount of wire or turns of wire? Or should I completely take the ride down to nothing and put my own windings on it? And or or taps

HI MIKE. KB1OKI HERE ED, WHAT ARE THE CHANCES YOU COULD HAVE A LOOK AT MY HALL. S120? IT WORKS BUT NEEDS SOME TLC... OR ANY IDEA WHERE I CAN GET IT LOOKED AT?WATCHING YOUR VIDS. I SEE YOU AS A GEINUS ON THESE OLD RECEIVERS. THANKS ED...

What about a Ring of Two RF preamp.

At 4:00 what is the top box. ICOM Model

Where can I find parts so I can hear am dexing

I'd like to see if a round ferrite "doughnut" from an old tv set would work.

@MIKROWAVE1

4 жыл бұрын

The yoke ferrites are similar to FT240-61 so they would be good for making baluns if you glued the the two halves (some are split). But I am not so sure they would be good for making high Q inductors to tune a front end with. www.yumpu.com/en/document/view/18662717/free-ferrite-from-tv-sets-in-balun-use-py2wm

@sarahhoward9081

4 жыл бұрын

@@MIKROWAVE1 thanks. After I thought about it I realized that would probably be the case. The thing is I've been scrapping lots of old TVs and I have some enormous ones I just couldn't let myself throw away. Some of them are 4 or 5 inches diameter. Any suggestions on a purpose for them? Obviously these came from bigger picture tubes than they were able to make with the iron powder ferrite and the scratch test confirms they are more ceramic-like. I tried sticking half of one inside a toilet paper roll crystal set I made a while back and moving it back and forth as an experiment and didn't get any noticable result.. also would you think that magnetic fields could be utilized to affect a crystal sets performance? Kind of like a voice coil and humbucker coil in a non permanent magnet speaker, only, hopefully, opposite. In other words an external magnet could be used to accentuate the coils magnetic field, or cancel it out perhaps. Just thinking out loud. Thanks for the teply:)

What about using a MC1350 RF Preamp chip, What about an UNUN to match the long wire antenna to the radio set.

@MIKROWAVE1

3 жыл бұрын

I always loved the old 1350. In fact that was a go to chip for many projects in the 1980's. I have one in my QRP XCVR as the IF.

Does ferrite outside the length of the coil have any real action?

@MIKROWAVE1

4 жыл бұрын

Increasing ferrite or powdered iron rod length and diameter act to capture and concentrate magnetic fields more efficiently. The null depth is also improved with length. So yes.

I couldn't see how the ferrite antenna showed the null at the 4:50 point in this video. If it was shown on the ICOM, it wasn't very clear.

@MIKROWAVE1

3 жыл бұрын

The LCD meter on the ICOM is nasty, but you can get it to null. A real analog meter would be a better indicator.

Thank you. What do you think about material 77 ferrite rod?

@MIKROWAVE1

3 жыл бұрын

That material is is very high Ui and would be good for LF. It would be useful for the BCB, but no higher in high Q tuned mode.

How matching this antenna with lower imput impedance mean calculate number secndary turn

@MIKROWAVE1

3 жыл бұрын

It is basically a square law. So halve the turns ratio = 1/4 the impedance.

@salahibrahim633

3 жыл бұрын

@@MIKROWAVE1 thankyou

@salahibrahim633

3 жыл бұрын

If i now the the imput impedancce is25 hom can you explain me by exemple

I don't speak german, but it does sound about 80 percent like him. It does seem he is speaking rather rushed in this reconstruction.

What he called duct tape is not duct tape - I don't think

@wematintramp5264

5 жыл бұрын

I'm pretty sure the brand name he is using is called DUCK , but it is packing tape. Duck also makes Duct and other types of tape. 73s Steve KB9SIH

Hello, dear engineer. Really, both parts of this video were perfect and perfect in every way. I want to be honest, for several years, whenever I came across the subject of the frame of those AM radios and the issues related to them, I always had questions in my mind. It remained that even after searching on Google and reading several pamphlets due to the scattering of the contents, I still did not understand exactly...points such as cutting the ferrite rod or whether it is possible to glue two ferrite rods together or not. Where is the most suitable place to place the coil on the ferrite rod and... I wish you success and health. Alireza from Iran

Good work... I love to watch that old equipment being put to use... Baluns... here is a page Id like for you to comment on... www.vkham.com/Info/ferro/balun_winding.html The designs that is... You might add your knowledge to this page in a third video of ferrite rods.