Alberto di Bene wrote:

José de Sá wrote:

> What about the TS-870 or the Icom IC-746 ?

I owned or still have most of the receivers you mention.
The TS 850 is a good rx on LF and so is the TS50 and TS570 with the
appropriate IF filters.
Other makes that are acceptable are the FT1000, IC746, IC706 and FT847
Others I do not know about because I have never tried them.
With large antennas all the above are good with smaller antennas there
might be a sensitivity problem.
In my case I have adequate sensitivity because of the fairly large
antenna system.
With suitable filters the TS850/TS50 and TS 570 are good on 136 khz and
comparable are the FT1000 and IC746. The IC706 will just about manage
with the pre amp ON with a large antenna and an external audio DSP
filter. With smaller antennas the IC706 is barely sensitive enough.
The FT 847 although useable suffers from overload, but with some
attenuation and juggling it works.
All of the above receivers are good enough with a good antenna for 136
khz and a lot depends on the OPERATOR regardless of specification.
You must have the necessary narrow cw filters for maximum performance on
all the above receivers.
If you need 73 khz then you are more limited for choice as most do not
cover that frequency.

G3KEV
>
> Jose  CT1EEB
>

According to the Kenwood specs, the TS-850 is rated at 0.2 uV for
10 dB (S+N)/N at 100 kHz.

The TS-870 has a rating of only 1 uV in the same conditions.

Don't have numbers for the IC-746, but a friend OM that owns one
tells me that it is deaf as a doorknob on the LF band.

73  Alberto  I2PHD