"John Plimmer" wrote (in part):

snip
That's very strange indeed, as the 7030+ has the highest blocking specs
of
any hobby receiver and higher than some very expensive professional
receivers.
snip

I had the good fortune to have a 7030+ to play with for a couple of
weeks.
I would sell kidney or other spare body part tonight to buy one.
However I live less then 4 miles from a littlel 1KW MW on 770.
And we a few fairly local power houses at 590 and 630 and 1300.
On the 7030+ I could receive the 770+590 fairly strong the , the
770+630
and and the 770+1300 very strong. In a nearby park about twice as far
from the 770 station as my home, I get no mix products. The 770 is so
strong that it will show up in most receivers even with the antenna
disconnected and replaced with a 50 ohm terminator. By most receivers
I mean R390, R392, R5000, R2000 DX389(3.5mm plug inserted),
the 7030+ and every automotive radio I have ever tested. I suspect
that
the 770KHz is so strong is just causes the front end to "colapse".
It is funny that my PRC1000 requires at least a paper clip to receive
it.

I can receive them on a simple crustal set with just the leads to the
earphones.

I am very glad they are only 1KW and daytime only!

Terry

"John Plimmer" wrote (in part):

I would sell kidney or other spare body part tonight to buy one.
However I live less then 4 miles from a littlel 1KW MW on 770.
And we a few fairly local power houses at 590 and 630 and 1300.
On the 7030+ I could receive the 770+590 fairly strong the , the
770+630
and and the 770+1300 very strong. In a nearby park about twice as far
from the 770 station as my home, I get no mix products. The 770 is so
strong that it will show up in most receivers even with the antenna
disconnected and replaced with a 50 ohm terminator.

Is there any possibility that you have the rear-panel pre-amp turned on in
the 7030?

What happens when you add in 10 dB or so of attenuation?

Rick Kunath

Rick Kunath wrote:
"John Plimmer" wrote (in part):

I would sell kidney or other spare body part tonight to buy one.
However I live less then 4 miles from a littlel 1KW MW on 770.
And we a few fairly local power houses at 590 and 630 and 1300.
On the 7030+ I could receive the 770+590 fairly strong the , the
770+630
and and the 770+1300 very strong. In a nearby park about twice as far
from the 770 station as my home, I get no mix products. The 770 is so
strong that it will show up in most receivers even with the antenna
disconnected and replaced with a 50 ohm terminator.

Is there any possibility that you have the rear-panel pre-amp turned on in
the 7030?

What happens when you add in 10 dB or so of attenuation?

Rick Kunath

I tried adding 10 db attenuation and even more, but it didn't help.

Steve

In article .com,
wrote:

Rick Kunath wrote:
"John Plimmer" wrote (in part):

I would sell kidney or other spare body part tonight to buy one.
However I live less then 4 miles from a littlel 1KW MW on 770.
And we a few fairly local power houses at 590 and 630 and 1300.
On the 7030+ I could receive the 770+590 fairly strong the , the
770+630 and and the 770+1300 very strong. In a nearby park about
twice as far from the 770 station as my home, I get no mix
products. The 770 is so strong that it will show up in most
receivers even with the antenna disconnected and replaced with a
50 ohm terminator.

Is there any possibility that you have the rear-panel pre-amp
turned on in the 7030?

What happens when you add in 10 dB or so of attenuation?

Rick Kunath

I tried adding 10 db attenuation and even more, but it didn't help.

Describe your antenna.

Does your antenna have any mechanical connections that could be lose or
have rust between conductors?

Besides poor connections forming diodes out of oxides it could be that
your antenna is exceptional at picking up AM broadcast band. Are any
over S9 when tuned in?

--
Telamon
Ventura, California

I'm using a Wellbrook 330S antenna and I don't think it's suffering
from any problems. I use it with my other receivers and they seem to
function well with it. Occasionally there's overload on the HF-150, but
it's always pretty minor, not like what I'm experiencing with the 7030.
This makes me suspect the problem isn't with the antenna. I can even
connect my SW77 to this antenna without getting the kind of overload
I'm finding on the 7030.

Steve

In article .com,
wrote:

I'm using a Wellbrook 330S antenna and I don't think it's suffering
from any problems. I use it with my other receivers and they seem to
function well with it. Occasionally there's overload on the HF-150, but
it's always pretty minor, not like what I'm experiencing with the 7030.
This makes me suspect the problem isn't with the antenna. I can even
connect my SW77 to this antenna without getting the kind of overload
I'm finding on the 7030.

OK, it is not likely that this type of antenna would have the problems I
mentioned and the fact that another receiver you own does not seem to
suffer the same problem points away from the antenna being the problem.

As Pete has mentioned the 7030 has front end filtering but depending on
its age those front end filters could have a problem with the elements
they are made of and at one point were "upgraded" by AOR. The inductors
on some early units had inductors that would saturate and I don't recall
what the problem was with the capacitors but both were changed. Maybe
you have the inferior inductors and capacitors in the front end filters.

Pete already gave the link to the bulletin page but specifically I point
you to this http://www.aoruk.com/7030bulletin.htm#ip3

--
Telamon
Ventura, California

Rick Kunath wrote:
Is there any possibility that you have the rear-panel pre-amp turned on
in
the 7030?

What happens when you add in 10 dB or so of attenuation?

Rick Kunath
------------------------------------------------------------------------
Preamp was off.
Attenuation didn't mater.
It was reduced with a 50 Ohm termanator on the antenna
port but not eliminated.

Wasn't bad enough to be a problem, after all if a R390 and the R392,
completly shielded in a tough aluminium case with 4 1/4" bolts per side
of the front pannel, that amke good contact witht he front panel and
the
case, both received the 770KHz signal, I wan't suprised the 7030+
and almost every other receiver I have tried picks it up.

I would consider selling a kidney tonight, if legal, to get one. I
LOVED
the receiver. Sadly the ARM and QRN noise floor is my limiting factor,
even my R2000s don't reach their internal noise floor because of the
external crap.

But the selection of filters, the synch detector, tunning steps,
optional
PC control make the 7030+ my dream receiver. At my QTH any signal
I could receive with the 7030+ I could receive with either of R2000s.
But the synch detector is magic. The better filters allow listening to
weak signals that will give you a head ach on the R2000s. Signals
that are dificult to impossible to understand on the R2000 are hard
much easier to understand. I can't explain the difference, reminds me
of the tube/valve HiFi debate, but I will never be satisfied unitl I
have
my own 7030+. Even with similar bandwidths the 7030+ is the clear
winner. And it isn't just a pahse noise issue. Comparing it to a R390
and R392 in a friends fairly RFquite country home, the 7030+ beat
the R390 and R392 in weak signal "understandability". I don't have
a scale to measure it, or even words to really discribe it, but the
7030+ is just "cleaner". The R39X have "no" phase noise. I had
always writtensome of the less then perfect weak signal performance
of the R2000 to phase noise. I now know that isn't the whole story.
Don't get me wrong, for what I have in my R2000 they are great
receivers. Kind of like comparing a Toyota Camray to a Lamborghini.
The Camray will get you there, but the Lamborghini will really get you
there.

The only improvement for the AOR 7030+ that I can think of is a
90% price reduction.

I would gladly trade my PCs and all of my radios, ham gear included
for a 7030+.

Terry

In article . com,
wrote:

Snip

However I live less then 4 miles from a littlel 1KW MW on 770.

Snip

The 770 is so strong that it will show up in most receivers even
with the antenna disconnected and replaced with a 50 ohm terminator.

Snip

The 7030 has a metal case and so is shielded. This looks like a good
case of the BCB station coming in on the power cord through the house
wiring. With the 50 ohm resistor on the antenna terminal use a RF choke
on the DC power cord to the radio to see if the AM station goes away.
Same should work for any other radio that has a metal case.

The non-shielded radios may have the RF go through the case as an
additional path to consider.

--
Telamon
Ventura, California

Telamon wrote:


The 7030 has a metal case and so is shielded. This looks like a good
case of the BCB station coming in on the power cord through the house
wiring. With the 50 ohm resistor on the antenna terminal use a RF choke
on the DC power cord to the radio to see if the AM station goes away.
Same should work for any other radio that has a metal case.

The non-shielded radios may have the RF go through the case as an
additional path to consider.

--
Telamon
Ventura, California
--------------------------------------------
I can only wish I had my own 2030+. This was a borrowed unit
from a friend who was wrapping up the sale of her family farm
after graduation. I did try to place several ferrite RFI "snap on",
and while I could reduce the interference, even with over 10
on the power cord I still had a very weak signal on 770 and the
770+590.

I was really suprised by the R390 and R392. In these receivers
the RF was getting in through the audio line. High level RF is hard
to completly supress. At least the 770 station cleaned up their
harmonics. A nice letter with the comment that I would hate for them
to get fined for improper operation got the problem solved within
a week. The 1540, 2310 and 3850 were very strong.
No 4rth harmonic at all.

A high pass filter ruled out my receivers.

I wonder how many people have MW ingress and don't know it.
Sometime "real soon" I am going to psot the results of my RF
week end and how bad normal single or double brain only coax
is. By bad, I mean allows LW/MW and HF if any stations are
close or strong enough to leak in even with out an antenna connected.
I tested 100' of various good quality (Belden) coax. and one run of
200' (borrowed) run of triax.

Terry

Terry

I considered this, but I think the problem is too severe...especially
since the HF-150, with its notiously weak front end, is not as badly
affected. Also, tonight I noticed an image not just of a powerhouse
broadcast station here in NYC, but of a relatively strong shortwave
signal (Radio China International). I think a little bench time is
required to correct this problem.

Steve