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Old September 9th 03, 06:20 PM
Helmut Wabnig
 
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Default MFJ 269 schematic?

On Mon, 08 Sep 2003 18:41:51 GMT, Allen Windhorn
wrote:

I just bought an antenna analyzer from MFJ, MFJ-269. Seems to work
pretty well, though I have a little doubt about the accuracy. Anyhow,
when I bought it from Burghardt, the technician there assured me that
it included a schematic as part of the manual, but when I got it,
there wasn't one. Has anyone received a schematic of this device?
If so, could I possibly get a copy? How about calibration methods.


Calibrate what?
Where is the problem?

use several ohmic resistors, carbon type,
and measure SWR and Rs.
X should be zero at 50 Ohm
if the resistors are HF usable.

use capacitors with known value, etc., use coils.
use cables of known length.

use your brain.
THINK.


w.
--
On the Internet nobody knows that I am a dog.

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Old September 9th 03, 06:23 PM
Helmut Wabnig
 
Posts: n/a
Default

On Mon, 08 Sep 2003 18:41:51 GMT, Allen Windhorn
wrote:

I just bought an antenna analyzer from MFJ, MFJ-269. Seems to work
pretty well, though I have a little doubt about the accuracy. Anyhow,
when I bought it from Burghardt, the technician there assured me that
it included a schematic as part of the manual, but when I got it,
there wasn't one. Has anyone received a schematic of this device?
If so, could I possibly get a copy? How about calibration methods.


Calibrate what?
Where is the problem?

use several ohmic resistors, carbon type,
and measure SWR and Rs.
X should be zero at 50 Ohm
if the resistors are HF usable.

use capacitors with known value, etc., use coils.
use cables of known length.

use your brain.
THINK.


w.
--
On the Internet nobody knows that I am a dog.

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Old September 9th 03, 08:06 PM
Helmut Wabnig
 
Posts: n/a
Default

On Mon, 08 Sep 2003 18:41:51 GMT, Allen Windhorn
wrote:

I just bought an antenna analyzer from MFJ, MFJ-269. Seems to work
pretty well, though I have a little doubt about the accuracy. Anyhow,
when I bought it from Burghardt, the technician there assured me that
it included a schematic as part of the manual, but when I got it,
there wasn't one. Has anyone received a schematic of this device?
If so, could I possibly get a copy? How about calibration methods.


Calibrate what?
Where is the problem?

use several ohmic resistors, carbon type,
and measure SWR and Rs.
X should be zero at 50 Ohm
if the resistors are HF usable.

use capacitors with known value, etc., use coils.
use cables of known length.

use your brain.
THINK.


w.
--
On the Internet nobody knows that I am a dog.

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Old September 9th 03, 09:39 PM
JGBOYLES
 
Posts: n/a
Default

Has anyone received a schematic of this device?
If so, could I possibly get a copy? How about calibration methods


Allen, As another poster suggested (or demanded), you can check the calibration
of the 269 with some standard values of R, L, and C. If it turns out that it
does need calibration, then you will need a schematic, and a calibration
procedure. W8JI web page has the cal. procedure for the 259B. I don't know
how much of that applies to the 269, but they should be very similar. I have
not done a cal. on my 259B, but it looks quite involved, there are pages of
steps. Not just a matter of tweeking a couple of pots, or just really
*thinking* as another poster implied.
73 Gary N4AST
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Old September 10th 03, 01:04 AM
Art Unwin KB9MZ
 
Posts: n/a
Default

If you go to w8ji.com
the directions for calibration are well laid out.
These instruments are known to loose their calibration so it
is advisable to make a copy of the instructions.
If you send it back to the manufacturer then it will
be weeks before you get it back and it probably will
not be calibrated correctly anyway.
Have no idea what Helmut is trying to say as there is
not any external adjustments one can use by responding to a
particular measurement, so he is the one to put his thinking
cap on instead of pointing the finger at you !
Good luck
Art

Helmut Wabnig wrote in message . ..
On Mon, 08 Sep 2003 18:41:51 GMT, Allen Windhorn
wrote:

I just bought an antenna analyzer from MFJ, MFJ-269. Seems to work
pretty well, though I have a little doubt about the accuracy. Anyhow,
when I bought it from Burghardt, the technician there assured me that
it included a schematic as part of the manual, but when I got it,
there wasn't one. Has anyone received a schematic of this device?
If so, could I possibly get a copy? How about calibration methods.


Calibrate what?
Where is the problem?

use several ohmic resistors, carbon type,
and measure SWR and Rs.
X should be zero at 50 Ohm
if the resistors are HF usable.

use capacitors with known value, etc., use coils.
use cables of known length.

use your brain.
THINK.


w.



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