|Joined:||Thu, Mar 6th 2008, 13:50||Roles:||N/A||Moderates:||N/A|
|RF noise cancelling at VHF frequencies.||Nov 20th 2012, 03:59||2||2,142||on 20/11/12|
|SWEEP testing a radio from the Mike jack.||Jun 4th 2012, 04:57||3||1,133||on 4/6/12|
|Power Line Interference.||Sep 23rd 2011, 01:07||6||2,262||on 11/5/12|
|AM Carrier Level on Kenwood TS-2000||W2NJU||15 hours, 50 minutes ago|
|I work AM with this unit so here is my setting and why.
The CXR setting for SSB is 27.
On AM I run a CXR setting of 17. The power control is left at 25.
It does indeed have an effect on power output.
There is nothing in the user manual about the use of the CXR.
More important is the effect on dynamic power control.
This means if you were to run SSB setting for AM and look at an averaging power meter you will see the power go backwards on long peaks.
This is what I call the system 'attacking' the peaks and knocking down the average on short time intervals.
If you run the CXR setting down, it stops the ALC from attacking so aggressively.
The use of a Peak reading power meter can now see the modulation peaks without average reductions.
To go on, I use the CXR setting to set AM drive level to my amplifier.
Usually set for about 85 to 90 watts carrier.
At this level, 4 x the carrier gives you peak power to set the amplifier up to plus a little head room.
Setting the amplifier up this way and making sure you do not drive past ensures no flat topping should occur and working the amplifer over it's most linear part of the transfer curve..
With the TS 2000 set to 3k bandwidth and flat internal EQ, using outboard EQ and wide response mike make very fine clean audio within that range.
The 2000 brick walls at 3100 stock with no mods and will pass audio well below 100 hertz but I don't push the low end.
With this setup I run a $20 R.S. mike and no one can tell the difference between it and a $200 mike.
At an 80 watt carrier times 4 = 320 watts peak time about .9 for the modulation % limit set in the 2000 = about 288 watts AM +/-.
A nice increase over 90 watts peak from just the radio.
There is a lot to it if you look at all the parts and understand the associations.
|SWR/Power Meter Irratic||K6JMQ||on 17/12/14|
|In my opinion you have not received a reply that addresses your issue.
First, your antenna SWR needs to be matched down to within limits as specified by the mfger..
This is why your power meter shows you more power than the radio makes. The reason it the feedline actually sinks power that is being reflected back and forth between the antenna and the radio such that the 'vector sum' the meter reads, registers as more power. The meters don't know any different!
Your internal turner may not have enough range to handle the mis-match.
Turning the power down under these condition would cause the ALC action to never be achieved because the issue is outside the radio such that you did not accomplish anything by lowering the power.
Lowering the power does not affect the basic issue of poor antenna match.
Fix the antenna condition and the issue will clear.
|cable one digital box for cable tv||KD0NMZ||on 5/11/14|
|That's good to hear.
This is why it's best not to launch into all kinds of filters and other things before knowing what the source is.
|cable one digital box for cable tv||KD0NMZ||on 3/11/14|
|Your not being quite clear about the boxes.
Are there 3 boxes? Is only one affected? etc.
Has another box been tried?
What bands is the box responding to?
The cable boxes are not supposed to respond the your amateur signals especially at such low powers.
Until the interference mechanism is found no filter will help on a wild guess and a hope basis.
More questions; Is the box remote controllable with a hand unit?
If yes, what is the OFF command from the hand unit, as a start to analyze the possible similarity of command signal to your HF signal or harmonics.
Is the box a plastic type cover without any shielding?
This kind of analysis is needed to find a direction to go in; even then it may not be your responsibly for a box that has design issues you cannot overcome with any amount of effort.
|Stuff on 3840||W7WHY||on 4/7/14|
|Late to the party but need some opinion.
In contacting our Senators on matters of interference and behavior , I believe their staff and the Senator may not understand the gravity of what is being put forth in a complaint and needs help from some entity that has weight and access to them for consultation on serious matters.
It is difficult enough to get their attention on standard legislation and other matters without going technical on a regulated Hobby they know nothing about..
Is there any format or advice we need to have in pursuing these type of complaints if FCC field office action does not materialize.