Re: PL-390 External LW MW Antenna Mod

Laurence Mann

Thanks Rick,

Glad to know the '310 mod worked. I too am dismayed by the quality of the warped ferrite rods.

You asked about the ferrite in the '390 and how that radio compares to other ULR's. Well in my '390 the ferrite rod is 4 5/8 in (117 mm) long and 0.4 in (10 mm) diameter with two opposing flattened faces- a substantial improvement compared to the '310, which is the only ULR I have for comparison.

A rough and unscientific test, comparing weak and non-fading stations on the '310 and '390 radios, showed about a 5 dB RSSI and SNR advantage to the 390 consistent through LW and on up to around 1200-1300kHz on MW. The high end of MW (>1300 kHz) could be much closer between the two radios although I didn't have enough candidate stations to do more measurements so that is only a speculative conclusion at this stage. A sig gen driving a standard loop a la Gary DeBock's tests would be needed to sort this out.

Laurie Mann
Perth, Western Australia

--- In ultralightdx@..., Rick Robinson <w4dst@...> wrote:

Hello Laurie,

You've got to wonder what is going on with Tecsun and these "warped"
bars. I got a new PL-310 last week and it has one of the crooked bars
in it just like your '310 and '390. Within 2 hours of receiving my new
'310 I had installed your antenna mod and rewound the bar antenna.
Thanks again for posting that mod. That makes for a much more
versatile MW antenna setup. Now I can plug and unplug my 20cm bar
antenna at will.

How is the '390 performing down under compared to other ULRs? Also how
long is that bar? I did notice that the '310 has a 10cm bar compared
to the 8cm bar in the '380.

Hello All,

I recently received the Tecsun PL-390 and I have performed a mod to use the existing FM/SW antenna socket to accommodate external LW/MW antennas, as was done with the PL-310. A file documenting the procedure for the PL-390 mod has been uploaded to the Files area.


Laurie Mann
Perth, Western Australia

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