Frog Sounds 40m transceiver kit

Discussion in 'QRP Corner' started by K5DH, Feb 6, 2016.

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  1. N7EKU

    N7EKU Ham Member QRZ Page

    Hi Pekka,

    Cogratulations on your first QSO in 50 years! Three cheers for you! Hooop - hooop - hoooray!

    It should be your hand touching pin 3 on the lm386 to inject some audio signal, not pin 1.

    For the 2n7000, the danger is of static electricity on the gate (Pin 1). Shorting pins 2 and 3 is fine. Regardless, do like I do beforehand, and touch a grounded or large size unpainted metallic surface before working on any radio pieces.

    Do you have a dummy load or can you turn the power way down on your other rig? If so, you can use that to see if your frog sounds can receive a signal (if your rig can transmit CW on the right frequency).

    73 :)

  2. KB9BVN

    KB9BVN Ham Member QRZ Page

    I've had fun building these little rigs too...spend more time trouble shooting the shoddy components than anything else. My the kit, toss the caps in the trash and buy new ones. It'll save you some trouble...also socket that crystal so you can swap out close 40m rocks.

    On the other hand...go to and spend $49 on one of his One Watter kits...all good parts, great PCB, and you can't beat the support.

    It's all about having fun though.
    KL7KN likes this.
  3. OH1LA

    OH1LA Ham Member QRZ Page

    Local OH1 ham told me:
    "Sorry that I've forgotten the job. But in the antenna circuit there is a crystal that can bypass and the other crystal is vxo that can be transmitted by W2. The antenna circuit can be bypassed, or then try to touch the antenna directly from the 602's 1 pin, if it is there is a fault in the antenna circuit before the crystal.
    You can test your audio with your own crocodile disturbance by touching the 386 pin 3 with any metal object that is in contact with you, that is, your hand, even if it is a pin. It should be hurried. The audio line leaves the NE602 pin 4
    Test the audio line first if the dust drops from the surface of 602's 4 so the fault is on the RF side".
    and more:

    "Q2 is mute, it cuts audio from 386 to the headphone jack when you press the key. You can also listen to audio from 386 5 tapes with some delicate headphone, from 5 to 5.
    The listening passes through the amplifier and Q2 directly to the headphone so it is part of it. Feeling is the logic chain down to the right".

    73 de Pekka, OH1LA
  4. OH1LA

    OH1LA Ham Member QRZ Page

    What is the correct position for electrolytic capacitors. The pictures show the electrolytes installed how it hurts. I'm afraid that the device itself is in the wrong direction.
    The local amateur said the electrolytes were installed in the wrong way!

    73 de Pekka, OH1LA
  5. KA0USE

    KA0USE Ham Member QRZ Page

    i got one of these, along with a couple of pixies.
    THANK YOU!! for giving the clueless (that would be me) this truly useful information.
  6. KA0USE

    KA0USE Ham Member QRZ Page

    my thanks to all of you who have provided guidance. i don't have an o-scope or a transistor/cap tester, but i found the latter on ebay. they run $20 to $30. =/-. will score one of those. i do have a dmm.
    now to get a selection of parts. looking on ebay i note most of these are from china. if the description doesn't indicate, does that mean made in usa?

    i guess everyone does this, but i'm going to use muffin pans (MMMMMMMMMM, muffins!) to sort the parts/values. my aunt doesn't use them anymore, but you know how THAT goes- as soon as i get all the spaces with something in each one she'll want to make (actually, want ME to make) blueberry muffins. i may shop the thrift stores... AFTER we eat the muffins!
  7. KA0USE

    KA0USE Ham Member QRZ Page



    i hope this helps! i haven't opened my kit yet. does the board have polarity markings next to the components?
  8. W7UUU

    W7UUU Super Moderator Lifetime Member 133 Administrator Volunteer Moderator Platinum Subscriber Life Member QRZ Page

    Nice thread - glad it got resurrected. I enjoy reading a long thread where fellow hams work out technical problems and make progress, and no arguments or insult matches ensure. Nice :)

    AB2YC, AD5HR and N7ANN like this.
  9. KB0MK

    KB0MK Ham Member QRZ Page

    Old thread, but I had no audio also. Distinctive hum on pin 3 of LM386. Found out bad inductor L1. It was open.

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