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I have this one good on rx but poor on tx whizz loop antenna by moonraker there are two versions starting from 7 or 14mhz

A really cheap and simple option worth trying is an indoor dipole. Check out this page, http://www.swharden.com/wp/2010-02-07-simple-diy-stealth-apartment-antenna-for-20m-and-40m/, and omit the 20m

The NPN's powered from the "TX" 12v rail do not get power unless the PTT switch is pressed to transmit. I suggest you concentrate on the receiver first. When checking out the transmitter, no need to

Ola amigos Estou pensando em comprar esta fonte portatil? para um linear de 40m ...já cansei dos QRPps com esta propaga??o...rerere http://www.oreillyauto.com/flux-capacitor.html (

You may be very lucky here, everything could just work.? The transistors are all protected by a diode or resistor or both. I suggest you just put everything back together and see if the receiver

It is certainly possible that I reversed the supply leads - all of the other wiring looks ok but I might have simply put the spade connectors on the wrong way round. I used the battery because it's

Is it possible that you did reverse the power supply wires into the Bitx40? That battery is quite small. Could be the battery didn't have enough power to blow the LM7805, but was able to blow D7. When

That's very interesting! Many thanks for testing. I will try on my own BitX and see if I can reproduce this. Will keep you posted. 73 Allard PE1NWL

Arv, I've been looking into what might happen if somebody reversed the 12v power supply leads into the Bitx40. Have found that the LM78* regulators would not protect what lies behind them. ?(But an

The battery is a 1.3Ah 12V sealed lead acid battery.

Ok Cesar, I don't think you'd fry your counter, the freq amplitude directly from the Raduino is pretty low, if unsure just make voltage divider with a potentiometer and feed the counter through a

O'Reilly Auto Parts has them listed but do not seem to be for sale at this time http://www.oreillyauto.com/flux-capacitor.html DuWayne KV4QB -- DuWayne? KV4QB

If you are worried about not having a blocking cap on the frequency counter then unplug the connector that you have attached to "DDS1" and measure right off of that. There is a blocking capacitor on

That's good news! If it displays ok, the output from the Si5351 PLL chip is likely ok too. I can't imagine why D7 blew unless it saw reversed power supply leads. Could be that you have a power supply

What frequency should I get if I attach a freq counter to te dds connector? At 7.000mhz on the dds I read 5.005,687 on the fcounter

I have a freq counter but I don't want to fry it. I mean, where do I tiuchbwith the wire in order to pick freq without overloading the fcounter thanks

Jerry KE7ER I'm confused. How does one get a negative output from a 3-terminal regulator with input shorted. Where does the negative voltage come from? I see that we are almost neighbors. I'm in

The raduino is fine in as much as it powers up, displays frequency etc. I can't test the DDS output of it so it might not be completely fine but looking ok so far. Raj: what voltage should I expect

Just power the Raduino from a USB cable to keep all other circuitry quiet and attach a small wire to the DDS connector, you should be able to pick the signal on a nearby receiver on CW then zero beat

Both will work, and both will have similar challenges as you can’t fool Mother Nature. The (extremely) short loaded vertical will have low efficiency and narrow bandwidth, and will require a tuner.