S-350 DL - Just Another Junky Portable Radio

S-350 DL - The German-Chinese Made SW Portable Analog Only Radio with a
digital readout without the fancy preset buttons and PLL circuitry. A good radio for the wire antenna experimenter that are dealing with cheap portable radios with huge antennas! also good for preselector designers. A good start for beginners using analog dial radios anyways also just a radio for general strong broadcast SWL DX.

This radio acts and performs like a poorly made SW analog portable radio without the digital pushbuttons, and
memory presets that other digital radios used for a long time, but the drawback..... Poor sensitivity and
SW HF harmonic overload problems when strong signals are preset at night on the SW 1 bands! My SW boombox
really performs just like this radio! GCC Engineering will soon be the doctor to remedy the problem in dealing
with harmonics during the night. I have dealt with this problem since 1991 in lab kit radios and cheap analog
portable radio with AM.


The radio was received during Christmas during Dec 25, 2006. I have had the radio since then. Its been a good radio for FM DXing, but IBOC is standing out like a sore thumb from the local radio stations that needed to be DXed. The AM is not that bad, but there seems there has been a problem with AM when you connect the outdoor antenna to the radio it seems to overload with SW
HF harmonic interference. The SW band practically overload on the SW1 bands and it does not handle the strong signal stations that well, making DXing difficult than it needs to be. If you like to DX AM stations use a loop antenna not a outdoor longwire antenna unless it uses a preselector for example the MFJ-956, cause it will overload on the AM (MW) bands during the night with SW havoc. Remember this radio is made in China to keep in the cheap stages. This radio needs accessories like crazy such as preselectors, baluns, and fine tunable loop antennas with a 500 ohm impedance match. The good thing is that the AM and FM bands are good and accessible and also it tunes like an ordinary analog tuner. Please remember that you will need a preselector and attenuator for the SWL bands and lightning protection. Please make sure that this radio does not get dropped on the floor or get put in harmful conditions. This radio is really fragle. I want to share something with you and my friends on how to connect a simple
long wire antenna for general shortwave radio listening and yes its fully recommend that you use
a RF ground with this antenna configuration.

SIMPLE PROJECT: USING A POTENTIOMETER AS AN INDOOR ATTENUATOR

You can use a potentiometer as an signal attenuator for to decrease the overloading problem in indoor and outdoor antenna, especially large ones. What you need is a 100 K potentiometer and yes you still need an RF ground for outdoor types. This is something I came up with it was simple and basic there are other things for you to try out for long wire antennas.

This is an example of what I used to eliminate the overloading with the antenna while the RF gain simply doesn't help that much. You can use this simple circuit with other radios that use a plain old antenna wire with no ground connection or use it with a preselector or for a smart decision use it with a ground connection to eliminate interference mount the potentiometer in a box or anything you like to even a shielded enclosure will probably do better or use capacitors or extra resistors whatever your hearts content.

Coming soon I might use this design to use it with a active antenna and Yes a preselector circuit maybe rebuild a real good preselector that is doubled tuned and increase selectivity.