Re: PL-390 External LW MW Antenna Mod


I find that the sw sensitivity of the 390 is identical to a 310 that I had put an antenna equal in length to the 390. The 390 is more listenable, however, as weak signals are less choppy with the 390's reduced softmute (that's what makes this a keeper for me...not night and day difference, but easier listening). As to the mw band, the 390 is more sensitive than the 310 below about 1300 KHz. Above 1300, the 390 is similar to the 310. An oddity, however, that is not present on the 310 is images of daytime locals 90 KHz above the local's frequency (for example, I hear a clear mirror image of 1490 on 1580). Strange also is that I do not hear mirror images of locals located below about 1300 KHz on the dial. Anyone else note this quirk?

--- On Mon, 8/30/10, Kevin S wrote:

From: Kevin S
Subject: Re: [ultralightdx] Re:PL-390 External LW MW Antenna Mod
To: ultralightdx@...
Date: Monday, August 30, 2010, 12:12 PM

I have done a fair amount of comparing the PL-390 with my Sony 7600GR, and
have determined that the PL-390 is a bit better throughout the band: not a
big improvement or anything, but it does have an edge over the Sony. So,
the PL-390 stacks up quite well IMHO.

However, the 7600GR must have a separate LW coil on the ferrite, since it
is significantly more sensitive on LW than the PL-390.


> 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.
> Regards,
> Laurie Mann
> Perth, Western Australia
> --- In ultralightdx@..., Rick Robinson 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.
>> Rick
>> > 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.
>> >
>> > Regards,
>> >
>> > Laurie Mann
>> > Perth, Western Australia
>> >

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