MK484 AM receiver circuit
Description.
A simple AM receiver circuit based on the MK484 AM receiver IC from Rapid Electronics Ltd is shown here. MK4844 is a monolithic integrated circuit that has all the necessary sections of a AM receiver like RF amplifier, detector, AGC etc. The IC is available in TO92 package and requires very few external components.
In the circuit L1 and C1 forms a tank circuit. L1 also serves as the antenna coil. The audio signals available at the pin 3 of IC1 are amplified using the amplifier built around transistor Q1. C2 is a bypass capacitor while C3 is a DC decoupler. Capacitor C4 provides negative feedback while R4 biases the transistor Q1.
Circuit diagram.
Notes.
- Assemble the circuit on a vero board.
- Use a 1.5V cell for powering the circuit.
- Never give more than 2V to the circuit. It will destroy the IC.
- The MK484 can be operated over a range of 150 KHz to 3 MHz.
- For L1 make 90 turns of 36SWG enamelled copper wire on a 1cm diameter card board former. Experiment with thenumber of turns for getting optimum performance. A little trial and error is needed.
14 Comments
sir,ic mk484 or ys414 is not available in the market then which ic use in place of mk484.sir please tell me internal diagram of mk484.
Try using 2nos BC549C in Darlington configuration in place of ZN414.
Dear Mahendra,
Unfortunately my recent reply regarding the MK484 receiver does not
reflect any total sum to give an idea.The reason for this is the use
of an air type variable i.o. a plastic one.The cost difference is about
USD 10 plus for the former.The TA7642 sold by the recommended eBay seller
including postage should be around USD 10 for 10 pieces of TA7642 .The
output transistor should cost not more then 25cents each.
I have another suggestion about the receiver which can cost you a reasonable amount for a solderless kit including the earphones a
maximum of 15 usd excluding the battery unless you are able to collect the components for a lower price from Your local market.
I hope You have already constructed the received and the information will still be useful.
Please click on my name on top of the replies which will lead You to my
homepage where You will find a lot of info for Your future circuits.
Best Regards
Hello Arman Sabciyan
Thanks for giving such a nice circuit for AM receiver.I have to build this for my project.I want to buy all these component used in the circuit online.Can you suggest me any online website for getting all these .And please also tell me how much it cost around..(approximately).waiting for your reply.
Hello Dear Friends,
The circuit is not of mine. However widely available in the internet and linked from my webpage reflected below.My webpage content refers to several circuits using old components and in addition detailed info about the construction of ZN414 receivers or equivalent IC’s.
The webpage also gives an eBay shop selling TA7642 IC.Unfortunately the ZN414 is not available anymore or for a rather high price.So is MK484.
YS414 as far as I know should be available in India. LMF501 not produced
anymore.The most easy to find IC is the TA 7642 and for a very reasonable price from the eBay seller in Hongkong which I refer to.
The alternatives of TA 7642 are sold at a rather high price and high postage costs exceed the cost of the component.The above seller sells a pack of 10 .There is no need of investing so much money in order to find a ZN414 or MK484.
I apologize from those who have been for a reply since a long time.
Best Regards and Good Luck
Arman Sabciyan
TA7642,MK484,YS414,LMF501 not available in india,
There are several alternatives to ZN414.
These are TA7642,MK484,YS414,LMF501
All these four IC’s can be found the first much easier and cheaper.
The alternative of using 2xBC548 Transistors in Darlington configuration
may be one solution however there is no guarantee that a 1.5V AA Bettery
can be used with same performance.The BC548 transistors have three versions like A,B,C the latter with higher gain but this may mean more current consumption.I am currently working one using three BC548 transistors with good output.I will however recommend the use of 3x2N2222A transistors with two external leads reversed and lower current consumption.If interested You may use a BC517 NPN transistor or a PNP transistor BC516 both are two transistors in one
housing(case).Both versions are oroginal Darlington transistors.
You may find Darlington Configuration circuits for AM coverage but
most of them use 9V Batteries.One is already reflected among the circuts of this website with adjustable regeneration.
Regards All,
Arman Sabciyan
Equal to Transitor zn414 mk484 Ta7642
Hello to Everyone,
The MK484 type receivers are very interesting for good results with minimum number of components.
the MK484 the successor of ZN414 may not be found easily
except Chinese Market or by some retailers at a rather
high price.The current replacement is TA7642 .This chip
an be found easier. For BC548 you can use BC547 or BC108 or
2N2222 with equal results. For TA7642 please visit my
above mentioned homepage and related subject for a reliable source.
Good Luck and Experimenting
Arman Sabciyan
Hi Everybody,
In one of above texts I recommended the use of BC516 PNP or BC517 NPN
transistor being an alternative to any four of the ZN414- MK484-TA7642 or LMF501T IC’s to construct an AM Radio.Both of the former PNP or NPN transistors can be used in Darlington Configuration.The wording two transistors in one housing/case is erroneously mentioned.Both of them are single transistors and are recommended due to being manufactured in identical parameters.No need to add the use of either two PNP or two NPN transistors due to different battery polarity.
I appreciate Your Understanding,
Best Regards,
sir i required internal schematic dig of ic mk 484 because of this ic is not available in the market.
You want to replace the IC with discrete components, use 2nos BC548 in Darlington configuration. 1 emitter, 2 base and 3 collector. use ZN414 data if you want
please give me the internal schematic digram of ic mk484.
i need it very urgent.
thanks for sending me circuit of amplifiers, always liked the site