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7

Would the portable ~$40 Tecsun get damaged somehow by a 100-foot antenna because it's designed to work with shorter, portable antennas?  Unless you are within a kilometer or two of a very high power transmitter, there is no chance of your antenna collecting enough power damage your receiver. You are more likely to cause damage to your receiver from static ...


6

I signed up here just to reply to this great (the only one I could find on the internet) question/experience that helped me with an identical problem. I was so close to giving up when I read this thread and went to examine the component that looks like a coin battery (as the original poster described) and having owned a sucking hakko soldering gun, i ...


5

Tecsun is very similar to Baofeng in that anybody selling them expects a certain number of DOAs and other failures. They already know that QA on those rigs is directly reflected in the price. In the past I have had good success with getting vendors of like this to replace the radio body (no battery or antenna) simply by writing to them. I have gotten ...


4

I wouldn't risk directly connecting a 9.6v battery to a radio that expects 5-6v. The simplest solution would probably be the diodes mentioned in the comment to your question, but as the battery voltage dropped the voltage reaching the radio would drop as well, and as the battery got low the output voltage after the diodes might be too low to power the radio,...


4

Receiving is all about signal to noise ratio. If most of the noise is generated outside of the receiver (as it is on most HF bands) then matching the antenna system to the receiver increases the signal and the noise by the same amount so you have no change in the signal to noise ratio. Thats why the mismatched random wire works so well on HF receivers and ...


3

I listened to your samples and I can say that I've never heard interference that sounded like wind on a microphone before. It doesn't sound like typical RFI, but it still could be. It doesn't sound like clipping either. Regardless, some things worth trying (including those already mentioned in other answers, to be complete) are: Change the antenna; in ...


2

Have you considered placing an analog optical isolator in line?


2

I'm neither an electrical engineer nor a software-defined radio expert, but I have used WSPR, so I'll have a go at answering your question. You're correct that WSPR transmissions on 30m are centered around 10.1402 MHz, but the WSPR 2.0 User's Guide says that the passband is about 200 Hz wide since the software will generate tones between 1400 and 1600 Hz, ...


1

Your proposed big antenna could be too much for a cheap receiver. You probably will not blow any front end transistors, but MW or AM overload could give spurious responses, birdies, blocking, cross modulation etc. An experimental small series cap starting at say 10pF will improve matters by making the long antenna think that it is a short antenna. This ...


1

So, the magical relationship between antenna size and your receiver is that a larger antenna tends very much to have a larger effective area, which simply means it extracts field energy from a larger area that the radio wave you want to receive penetrates. In other words: you get more power at your receiver. That's cool, because more power means "more power ...


1

my Tecsun PL-660 hadn’t been used for a while. It didn’t charge the batteries either. I put the batteries in a separate charger and brought them up to full charge. Still no joy with them in the radio. Occasionally the display came on but not clearly and with various segments missing. Over the course of a few weeks and after a little research I removed the ....


1

30m WSPR signals can be anywhere inside the range 10,140,100 Hz to 10,140,295 Hz (which the software expects to see as an AF frequency of 1400 to 1595 Hz). The software simultaneously decodes at all frequencies inside that range looking for a valid signal, so that many transmitters can co-exist within the band — but it will ignore anything outside of that ...


1

Tecsun PL660 antenna is connected to the gate of the J-FET for frequency range 1700 kHz to 30 MHz. This is a high impedance. The measured graph can't be correct. The measurement signal voltage must be low enough to prevent switching diodes to go in conductive state. The FET transistors in the diagram have non-consistent gate-drain-source connections. The ...


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