Q-Multiplier Circuit - A Simple Circuit to Improve AM Radio Reception Works w/ AA5 or Transistor...

A simple Q-Multiplier Circuit designed by Raymond Haigh. The schematic and other cool projects by this author:
www.yumpu.com/en/document/rea...
The Ferrite Rod (Amidon) is a Type 61 material 0.5"D x 7.5"L. It's wound w/ Litz Wire 180/46-44 Special Blend (Inductance ~220 uH) from: www.mikeselectronicparts.com/...
The Variable Capacitor is also from Mike's Electronic Parts at: www.mikeselectronicparts.com/...
The two sections are tied together to get ~15 to 532pF.
The LC Circuit easily covers the (BC) AM Band.
I used a 100k potentiometer in lieu of a 10k and a 2N5457 JFET in my design w/ good results.
The one-sided PCB is 5cm x 7cm.
Q-Multiplier Circuit - Supercharge Your AM Transistor Radio Reception Daytime 60+ Miles
• Q-Multiplier Circuit -...
Schematic & BOM:
drive.google.com/drive/folder...
Thanks for watching and subscribing to my channel on vintage radio repair and other related circuits.
#RestoreOldRadios

[@0tt0z]

Thanks for the video! That will give my son and I something to play around with. Have a good day.

[@RestoreOldRadios]

Glad you found it helpful. Have fun building it together. All the best. Don

[@ElectroRestore]

Thanks Don for building this and sharing it with us! This excellent demonstration video and schematic is just what I been needing to find! I live in an area with only one local station and they are off the air a lot! This will be a great addition to my bench!

[@RestoreOldRadios]

Glad it helped. It’s not a perfect solution, but it does improve the performance of a receiver. BTW - I added an earth ground to the circuit and it helped mitigate some of the noise coming from my lights, etc., in the shop. Have fun and enjoy. Best, Don

[@jimnewman5596]

A great little circuit Don, the Yumpu document has a lot of great content.

[@RestoreOldRadios]

Jim - lots of cool projects for sure. I know you’ll be building a few of them; have fun. Best, Don

[@KetkAiball]

Hi Don. What I liked the most was the assembly you have done, clean and well organized on the printed circuit board. A very good work. Have a good day. Ketk (From España).

[@RestoreOldRadios]

Ketk - thank you. It’s a quick and simple circuit to build that works rather well. Thanks again for watching and reaching out. Best, Don

[@jdmccorful]

A very nice successful circuit. Thanks for the look.

[@RestoreOldRadios]

Thanks for viewing John. Best, Don

[@saturn5tony]

Thanks for all the great schematics and links as well Don...fun stuff!

[@RestoreOldRadios]

You are welcome Tony. Some real interesting circuits to review/study. Thanks for watching. Best, Don

[@ianbutler1983]

Excellent Don. I'm heading over to look at the schematic now. Thanks.

[@RestoreOldRadios]

Ian - thanks for checking it out. There are many more useful circuits at that link as well. Enjoy! Best, Don

[@rciancia]

really nice job Don.... that works terrific !!

[@RestoreOldRadios]

Thanks Ron. Lots of noise from the Thunderstorms today, but it seems to make these old receivers come alive. Best, Don

[@RadioRetired]

Wow what a difference. Great demo.

[@RestoreOldRadios]

Thank you. It seems to work well. An external earth ground was found to help with the localized electrical noise too. Best, Don

[@rajesh00ify]

Great job. Thank you for sharing.

[@RestoreOldRadios]

Thank you for watching and reaching out. All the best. Don

[@tinkeringwithelectronics]

Don, thanks for testing this with a tube radio. I guess it’s time for me to start gathering up the parts.

[@RestoreOldRadios]

I was glad to do it. Just head ever to Larry’s warehouse and gather up the parts you need. LOL Keep me posted if you build it and the results afterwards. Thanks for watching Josh. Best, Don

[@dz-abouttechnique1849]

Nice video!

[@RestoreOldRadios]

Thank you. All the best. Don

[@tectalabyss]

Thank you Don.

[@RestoreOldRadios]

Thanks for watching Bobby. Take care and all the best. Don

[@VintageElectronicsGeek]

Impressive and awesome! ~Jack, VEG

[@RestoreOldRadios]

Thank you Jack. I appreciate you watching. Best, Don

[@orgncc]

First of all, thank you very much for your video. Since I don't understand the circuit diagram, I would like to trouble you to take pictures of the front and back of the circuit board. I want to make one by myself according to the photo. Thank you for your help!

[@RestoreOldRadios]

Sorry, I no longer have the circuit. I used the parts for another project. You can refer to the video description for a link to the circuit documentation. I hope this helps. Thanks for watching and reaching out. Best, Don

[@vintagetransistorRadio.Radio.h]

Thanks.. Sir.. Sir.grate

[@RestoreOldRadios]

Thank you for watching. Best, Don

[@youyoo3408]

Ive had limited success with a magnet, but this is much better.

[@RestoreOldRadios]

Glad you found it helpful. Enjoy! Best, Don

[@jimdukarich1692]

As always, a very useful tool. You may or may not agree but it is a shame what has happened to the AM band and how little of quality there is to listen to. Doesn't change a bit what you are doing. Thanks. Jim

[@RestoreOldRadios]

Yep, I’m in a market with many AM stations, but the content is primarily Talk Radio. I enjoy my oldies using my close proximity TX. Hopefully a few folks can use the circuit to bring in some of the stations on the fringe... Thanks for watching and reaching out Jim. Best, Don

[@mohinderkaur6671]

Not just the AM band, FM band or TV or cable TV or any media at all- 1984 everything everywhere. All is BS and Propaganda "Safe and Effective" indeed

[@bachkhoa1975]

The Q-multiplier needs to be tuned to the same frequency that your AA5 receiver is tuned to; else your Q-m boosts some other frequency and your AA5 benefits little if any.

[@RestoreOldRadios]

Thank you. Best, Don

[@TheRadiogeek]

Very nice build. You did a nice job on winding the antenna wire. Did you get the bar from mike as well? 👏🏻👍

[@RestoreOldRadios]

Thank you. The Ferrite Rod came from Amidon. It’s a Type 61, 0.5”D x 7.5”L. Thanks for watching. Best, Don

[@TheRadiogeek]

@@RestoreOldRadios Thanks! Sorry I guess I missed that in the description. 😀

[@RestoreOldRadios]

No worries, I appreciate you watching. You’ll enjoy building and using the circuit if you decide to go forward. Best, Don

[@larrypozzi2201]

Hi Don. This is an interesting piece of equipment. I just received my Admiral back and checking for am stations and they’re terrible in my area. Is this something that you would be willing to build and ship? I’m interested in increasing my am options. Please let me know and thanks. Larry

[@RestoreOldRadios]

Hi Larry - It’s great to hear you got the Admiral back from Ron and I know it brings back special memories. I don’t think the Q-Multiplier would be well suited for your radio. Send me an email to TheRadioRepairGuy at gmail.com and I’ll expand on this and we'll discuss other options. Best, Don

[@BonifacioJose1763]

I did not understand the making of the coil in L3. Could you please explain how many laps please? thankful.

[@RestoreOldRadios]

Check out the video description and you’ll find a link to the author’s article that provides the details you are looking for. Best, Don

[@JohnnyUmphress]

That would be nice if it were designed around a nice spider web antenna instead of the ferrite rod.

[@RestoreOldRadios]

Johnny - that would be cool. It should be doable and I look forward to hearing back on your results if you elect to give it a try. Thanks for watching. Best, Don

[@omidsafari3555]

thanks . where can i find this circuit ?

[@RestoreOldRadios]

The link is in the video description. Thanks for watching. Best, Don

[@omidsafari3555]

@@RestoreOldRadios thank you very much🙏🙏

[@SnehasishDebnath_remo]

Can it be made for 3MHz to 108Mhz ? To support SW and FM band?

[@RestoreOldRadios]

Changing the resonant frequency of the oscillator should work for SW, but not for FM. Best, Don

[@SnehasishDebnath_remo]

@@RestoreOldRadios then what will be the best way to amplify FM signal?

[@RestoreOldRadios]

@@SnehasishDebnath_remo What kind of aerial (antenna) are you using?

[@SnehasishDebnath_remo]

@@RestoreOldRadios Still haven't build any, I have old TV antenna, I am thinking of reusing it as a FM antenna. Don't know whether it will work or not.

[@RestoreOldRadios]

It would be worth a try before investing in a dedicated FM antenna. Hope the results are positive if you go that direction. Best, Don

[@BrightBlueJim]

Your Yumpu page is impossible to read, it's so full of pop-up ads.

[@RestoreOldRadios]

Sorry, I don’t have a Yumpu page, I referenced the one in the show more (video description) for the author of the original circuit design. All the best. Don