Hi Stefan No probably I misunderstood your exchange
with Andi :-))
Alan
----- Original Message -----
Sent: Friday, October 23, 2015 11:32
PM
Subject: Re: LF: To DK7FC : measuring low
levels RF current.
Hi Alan,
Hm, do i misunderstand something now? Just
to make it clear: I certainly know how to measure a RF current on DC to HF and
above :-) Higher currents? Well, 20A is fine for me, otherwise the decca RF
sitz becomes to warm, not to talk about the high voltages ;-)
73,
Stefan
Am 24.10.2015 00:18, schrieb Alan Melia:
its 100ma/1A full-scale. Follow the
documentation, click under the pic and find the circuit and cal
procedure which should give a clue to reading higher currents
too.
Alan
G3NYK
-----
Original Message -----
Sent:
Friday, October 23, 2015 11:03 PM
Subject:
Re: LF: To DK7FC : measuring low levels RF current.
Hello Andi,
Thanks for the info. What does this
amperemeter cost? I think i would know how to build an amperemeter for
100 mA FS. However my ranges are 5A / 10A / 20A :-) I'm directly measuring
the antenna current, i.e. not on the 50 Ohm level.
73,
Stefan
Am 23.10.2015 14:53, schrieb F6CNI - Andy - JN19QB:
Helo Stefan,
For info, here I am using a MFJ 834 RF Ammeter. It is
working well on MF band, it just need to be first re-calibrate on MF
band (only one variable resistance to adjust) using a low power signal
into a 50 Ohms pure resistive load.
It is quite linear for RF current measurement from 25 mA to 3
Amperes, in 3 swiched scales.
Using it on the 50 Ohms coaxial cable, just after your TX
output, you have a good estimation of your TX power output from 30 milli
watt to 450 watts.
You can also use it on the cold end of the antenna side.
Depending at the overall antenna system resistance, you can read the
real antenna current…
73 de Andy.
Sent: Thursday, October 22, 2015 11:09 PM
Subject: LF: M0LMH
Hi
MF, Since a few hours i'm transmitting WSPR with the variable
mains transformer turned to 0%. So just the driver is switching the
FETs. Anyway a few mW TX power seem to be generated and radiated. I can
see no reading on the RF amperemeter. Anyway i got 15 spots:
Timestamp |
Call |
MHz |
SNR |
Drift |
Grid |
Pwr |
Reporter |
RGrid |
km |
az |
2015-10-22 20:14 |
DK7FC |
0.475685 |
-22 |
0 |
JN49ik |
1 |
M0LMH |
IO93gx |
862 |
310 |
2015-10-22 20:24 |
DK7FC |
0.475683 |
-19 |
0 |
JN49ik |
1 |
F5WK |
JN18hp |
452 |
261 |
2015-10-22 20:44 |
DK7FC |
0.475682 |
-21 |
0 |
JN49ik |
1 |
PA0A |
JO33de |
449 |
339 |
2015-10-22 20:14 |
DK7FC |
0.475682 |
-26 |
0 |
JN49ik |
1 |
PA0RDT |
JO11tm |
428 |
305 |
2015-10-22 20:14 |
DK7FC |
0.475683 |
-17 |
0 |
JN49ik |
1 |
PA3ABK |
JO21it |
386 |
315 |
2015-10-22 20:14 |
DK7FC |
0.475683 |
-15 |
0 |
JN49ik |
1 |
DH5RAE |
JN68qv |
345 |
98 |
2015-10-22 20:14 |
DK7FC |
0.475683 |
-18 |
0 |
JN49ik |
1 |
PI4THT |
JO32kf |
336 |
338 |
2015-10-22 20:14 |
DK7FC |
0.475683 |
-15 |
0 |
JN49ik |
1 |
DJ0ABR |
JN68nt |
329 |
101 |
2015-10-22 20:14 |
DK7FC |
0.475683 |
-22 |
0 |
JN49ik |
1 |
DG8RW |
JN69cv |
257 |
77 |
2015-10-22 20:14 |
DK7FC |
0.475682 |
-23 |
0 |
JN49ik |
1 |
DF2JP |
JO31hh |
256 |
325 |
2015-10-22 20:54 |
DK7FC |
0.475683 |
-27 |
1 |
JN49ik |
1 |
DC0DX_H |
JO31lk |
255 |
332 |
2015-10-22 20:24 |
DK7FC |
0.475684 |
-24 |
0 |
JN49ik |
1 |
DB1EPO |
JO31hg |
252 |
325 |
2015-10-22 20:14 |
DK7FC |
0.475684 |
-21 |
0 |
JN49ik |
1 |
DF6NM |
JN59nj |
175 |
91 |
2015-10-22 20:14 |
DK7FC |
0.475684 |
-7 |
0 |
JN49ik |
1 |
DK2DB |
JN48fw |
58 |
198 |
2015-10-22 20:34 |
DK7FC |
0.475686 |
-10 |
0 |
JN49ik |
1 |
DF8UO |
JN48ex |
56 |
206 | M0LMH is the best
distance. Also in daytime i can see that M0LMH is receiving me, often
beeing the only one from UK. Does someone know him and his equipment?
Would be interesting to know! In IO93GX, there is not population.
Certainly one reason for the good results... 73,
Stefan PS: Now
QRO...
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