My Radio Shack DX-375 problem
 

I cant get it to tune into frequencies like 3412 or 3413 or stuff like
that. only stuff like 3415 and 3500 etc. you know only falls on 5's and
10's why wont it go to any 2's or 3's 4's and 6's 7's 8's etc etc?

Hi,

I cant get it to tune into frequencies like 3412 or 3413 or stuff like
that. only stuff like 3415 and 3500 etc. you know only falls on 5's and
10's why wont it go to any 2's or 3's 4's and 6's 7's 8's etc etc?

AM shortwave broadcast stations are spaced at 5kHz intervals so the
receiver was probably designed with that in mind. For simplicity's sake,
they will have used a single loop design in the synthesiser with the
aforementioned 5kHz as the PLL reference frequency. Had the receiver been
meant for sideband/CW operation, it would then have had the ability tune
in smaller increments.

Generally you get what you pay for :-(


Cheers - Joe

Joe McElvenney wrote:
Hi,


I cant get it to tune into frequencies like 3412 or 3413 or stuff like
that. only stuff like 3415 and 3500 etc. you know only falls on 5's and
10's why wont it go to any 2's or 3's 4's and 6's 7's 8's etc etc?


AM shortwave broadcast stations are spaced at 5kHz intervals so the
receiver was probably designed with that in mind. For simplicity's sake,
they will have used a single loop design in the synthesiser with the
aforementioned 5kHz as the PLL reference frequency. Had the receiver been
meant for sideband/CW operation, it would then have had the ability tune
in smaller increments.

Generally you get what you pay for :-(


Cheers - Joe


But some of these sets did have a 'claifier' or 'fine tune' knob that
pulled the reference rock a little to allow for off frequency stations
and SSB. For ssb you could also just move the BFO a bit too.
The RS rx in question probably doesn't have either of these controls.

On Sun, 29 Aug 2004 09:05:25 +0000 (UTC), Joe McElvenney hath writ:

I cant get it to tune into frequencies like 3412 or 3413 or stuff like
that. only stuff like 3415 and 3500 etc. you know only falls on 5's and
10's why wont it go to any 2's or 3's 4's and 6's 7's 8's etc etc?


AM shortwave broadcast stations are spaced at 5kHz intervals...

In your country, perhaps.

Devourment 420 wrote:
I cant get it to tune into frequencies like 3412 or 3413 or stuff like
that. only stuff like 3415 and 3500 etc. you know only falls on 5's and
10's why wont it go to any 2's or 3's 4's and 6's 7's 8's etc etc?

Because the designers didn't want it to do that.

--
"The truth, which is what elections are all about, is that the tax burden of
the middle class has gone up while the tax burden of the middle class has
gone down." -- John Kerry, August 26, 2004

On the SW bands, it tunes in 5kHz steps. On the MW band it tunes in 9 or 10
kHz steps, subject to your setup. Even though a station may transmit on a
frequency between a step, the selectivity is wide enough that the nearest
step will provide reception close to what it would be were it tuned right
on.

Tom

"Devourment 420" wrote in message
...
I cant get it to tune into frequencies like 3412 or 3413 or stuff like
that. only stuff like 3415 and 3500 etc. you know only falls on 5's and
10's why wont it go to any 2's or 3's 4's and 6's 7's 8's etc etc?

On 29 Aug 2004 18:24:11 GMT, drwxr-xr-x wrote:

AM shortwave broadcast stations are spaced at 5kHz intervals...

In your country, perhaps.

If you look at the WRTH _shortwave_ frequency list, much more than 95
% of the stations are spaced at 5 kHz multiples, as the ITU requires
them to be.

Those that are not, seems to have problems with their frequency
stability and may drift somewhere between. These are usually small
private stations, in which the equipment has been hacked up by some
local technician.

Paul OH3LWR