Many Justification for homebrewing,…
I found a good notes about homebrewing from JF1OZL sites
Kazuhiro Sunamura said:
This is wrong way of homebrew :
1.Reading the article on the book.
2.Buying the parts on the book.
3.Making the print board.
5.Checking the movement.
And if we are stay at a wrong way…. we always have a condition and do something like below:
1.Even if you could get the same type of transistor as the article on the book, you must arrange the bias current in many cases.
2.The parts supplier says “equivalent parts”. But that means that “you can use it , if you make some arrangement on the circuit.”.
3.If one part of the machine ( made by 100 of parts) were connected fail, the gear can not move.
4. As one of an author of the magazine , I must say that the circuit is printed wrong in sometimes. 1k ohm is printed 1 ohm in sometimes.
5.The pitfalls described above will wait for you. You will fall in each of them with the probability of 50%. You will reach the goal with the probability of 0.5*0.5*0.5*0.5=0.06 . Yes only 6%.
This is the right way of homebrew :
1.Reading the article on the book.
2.Understanding the block diagram.If the article shows only circuit, you must wright the block diagram by yourself.
3.Understand the movement of each blocks one by one. Foe example,if the main positive part of the block was IC, you must check as follows.
*Check the difference of the circuit between the article and the application circuit on the databook of the maker!
*Check the inner circuit on the IC! You must understand the movement of that IC as the transistor level.
*Check the impedance of the article is good for that IC!
*Check the signal level of the article is good for that IC!
*Check the power level (Vcc) of the article is good for that IC!
*Check the frequency of the article is good for that IC!
*Check the IC of the article is acceptable for you , or not! If the main part was transistor , you must check the same way.
4.Write the circuit with your stock. Foe example, LM386 must be used instead of LM380 on the article. Then you must check the Vcc, you must check that the 8 ohm speaker can be used or not.
5.Make the block one by one. And you must check the movement of the block one by one. The radio must be made from the power amplifier. The ssb transmitter must be made from the mic amplifier. Nobody will make transmitter from the final AMP. Sometimes you must make the pretest about the relation for the frequency of the machine. Therefore the pretest of the oscillator and filter must be made in some cases.
6.Check the machine on the board.
8.Here you came only half the way.
9.You must make some QSO with your local station. Receive the report!
10.I will describe about check point of SSB transmitter.
*You say ” sha-syu-syo-“! You can arrange the relation between the filter and carrier oscillator.
*If your voice vibrates on the top of each words (for example “action” can be heard like “Gaction”.), you must reduce the voltage of the signal of microphone amplifier.
*You must check the linearity of the final amplifier.
*You must check the hum.
*you must check about the self oscillation of the microphone wire and the antenna. Sometimes this phenomenon happens on the timing of peak power of the ssb signal.
*You must check the stability with the another power supply.
*You must test the transmitter with no antenna on the connector. On the top of the hill sometimrs the wire of antenna will be broken.
11.Apply to the association.
12.Somebody makes the case on the top of the project.
13.Do not afraid to fail! My project completes only 50% of these days
Up to you,…for make a decision about you are running on wrong way or right way of homebrewing….!!
Thanks For JF1OZL (Kazuhiro Sunamura) !
You are a trully HomeBrewer,……….