Dual SWR Meter setup tuning help.

[Handy Andy]

Hmm...not to confuse this anymore now that some SWR issues have been sorted out...

Remember you have an HD (High Drive) amp, it doesn't "sip" coffee to wake up in the morning...

IT guzzles it...

​

What used to need several mW or even a Watt, now needs a little more oomph so that means the SWR problem will need a different approach than a typical 1 Pill driving 4 type of scenario.

You have babies requiring milk...and they need to be fed to produce output...

​

Yes, output...you didn't specify...

So the SWR to a High Drive Amp will look like it's "not right" - because of the input network and the dynamics you're dealing with...

Too low - you're hitting a wall - they can't conduct their full cycle - the RF signal arriving is too weak...

Too High - you get slamming and FM-ing - and ... see above - top right...

So if you haven't really noticed, or you were just humming a tune as the muffler to the Chevy slowly eroded and finally fell off - you're left at a Stop sign wondering if the Cop on the other oncoming lane - whom is signaling you to go, is going to notice the extra noise...

So the High Drive amps are little more finicky on the kind of power levels, their dynamics (or swing) and the tuning you have to implement that allows for low- to high power loading swing to even work. In fact it's worse than s simple 1 X 4 - you know when you overdrive it, but Ooh! Does it float along nicely when it's just using 2 watts swinging 8...

The tuning network needs some help then when - YOU SEE SWR PROBLEMS WITH THE AMP ON ACCEPTING INPUT FROM THE RADIO - not a big deal but you will have the law of diminishing returns - the power dynamics needed to the High Drive Amp to use and need to make it swing are considerably different than a regular 2-Pill or a Modulator. The Network can be tuned for either a high power no swing output - or - low INPUT-power but limited high-swing levels - both are possible - you just can't do both at the same time...remember the SWR problem - you have to adapt an input network per pair of pills. So if you have 4 Pills, you will divide and conquer needing 4X the effort in power delivery than a simple 2-pill input.

 

[530]

Hmm...not to confuse this anymore now that some SWR issues have been sorted out...

Remember you have an HD (High Drive) amp, it doesn't "sip" coffee to wake up in the morning...

IT guzzles it...

View attachment 35373​

What used to need several mW or even a Watt, now needs a little more oomph so that means the SWR problem will need a different approach than a typical 1 Pill driving 4 type of scenario.

You have babies requiring milk...and they need to be fed to produce output...

View attachment 35374​

Yes, output...you didn't specify...

So the SWR to a High Drive Amp will look like it's "not right" - because of the input network and the dynamics you're dealing with...

Too low - you're hitting a wall - they can't conduct their full cycle - the RF signal arriving is too weak...

Too High - you get slamming and FM-ing - and ... see above - top right...

So if you haven't really noticed, or you were just humming a tune as the muffler to the Chevy slowly eroded and finally fell off - you're left at a Stop sign wondering if the Cop on the other oncoming lane - whom is signaling you to go, is going to notice the extra noise...

So the High Drive amps are little more finicky on the kind of power levels, their dynamics (or swing) and the tuning you have to implement that allows for low- to high power loading swing to even work. In fact it's worse than s simple 1 X 4 - you know when you overdrive it, but Ooh! Does it float along nicely when it's just using 2 watts swinging 8...

The tuning network needs some help then when - YOU SEE SWR PROBLEMS WITH THE AMP ON ACCEPTING INPUT FROM THE RADIO - not a big deal but you will have the law of diminishing returns - the power dynamics needed to the High Drive Amp to use and need to make it swing are considerably different than a regular 2-Pill or a Modulator. The Network can be tuned for either a high power no swing output - or - low INPUT-power but limited high-swing levels - both are possible - you just can't do both at the same time...remember the SWR problem - you have to adapt an input network per pair of pills. So if you have 4 Pills, you will divide and conquer needing 4X the effort in power delivery than a simple 2-pill input.

Thanks again for the awesome replies. To make it easier for you I am posting a link to an amp that is the same. I know I will hear about it from someone LOL. I am using just the 6666 to power it. The radio does 19DK/ 62 watts pep all the way up on a tone generator. All the way down its 3DK swings to 9PEP. I use all the way down for the swr tune. I was going to run it with about 50 watts pep in but again still investigating the HGs max input without overdriving them while taking into consideration its a "HD" amp, because I am reading there are a couple ways people are building a so called HD amp. What is your suggestion that this amp should be driven without overdriving it?

 

[Handy Andy]

The simple way?

(Gosh Darn It...)

Run your radio as if you are going into typical antenna - 50 ohm load - you want 3watts at least to keep the Pills going forward...(I'm referring to producing power...)

Unless I see something over my screen showing the "innards" of your amp - we can only speculate...

Because of what I've dealt with before...

IF you use a typical setup - you need 4 watts to 16 PEP - that is the typical CB radio does yes, but that is just to "Hold it up" and keep producing power.

Remember the bigger issue is with SWR. At least by what you saw.

So I'll kinda need the "low-down" on what has been done to the amp to help you...

So while you're at it, I need to you go back to that setup - once you have your antenna all tuned up? And you got the AMP loading into the Antenna - and you're ok with the SWR? (Hope 1.5 or less on this please)

Because then I'll need you to set up the SWR meter in-line TO THE AMP from the AT-6666.
Only this time - you only need the FWD setting readings - to get to Top of Calibrate on the meter face...

​

There is a trick to this...
I need to know, or what I'm looking for from you - so we get the reporting right...
How much power is being ABSORBED into the AMP - per power level setting...
Yes, there is an ideal "level" of power before the REF (your reflected power) starts to go up...
If the NETWORK was tuned right - there will be a "Window" where the amp will accept the highest level of power from the Radio - this you can see in the FWD setting and you compare it to REF...

This has to be done in steps...

What your FWD Meter setting CAL knob is doing - for the various power levels you can set your AT-6666
How far do you have to turn your CAL knob to meet "SET"? Naturally - you'd be seeing the CAL knob ACTUALLY GET TURNED DOWN once your power output from the radio goes up...True?
Well, that's Obvious....

He's watching ... you know...
​

Ok, you also need to know your REF power at that particular POWER IN setting - so we can see how much power CANNOT be used - So it is important to KNOW How Much POWER the Network needs - before we send too much power in and it starts REFLECTING MORE than what it uses - back...

So your know...

• You will always have REF power this is a loss to your effort to transfer power into a less than ideal load.
  • (So, yes, tune the ANTENNA for your LOWEST SWR BETWEEN THE AMP AND THE ANTENNA FIRST - so we don't add more complexity to the situation of POWER and where it's going)
• The Power going into the amp will approach a point of "no return on investment" NROI - the more power you put in - you don't get out - unless you want more heat.
  • This factor requires TWO meters, one at the Input and the other monitoring the Output. It would be nice to have, but not necessary at this point.
  • If you know of a Dynamometer - you see RPM versus Torque - we're looking for this same effect only we are looking at the ratio of FWD in to REF back to the Radio. Torque produces an ability to do work - RPM is the Rate of work - we are looking to see simple Carrier power and Audio "swing" ratio as we go up in power - pretty soon we will flat top out and not get any more swing - but we can still provide more carrier - IT IS AT THIS LEVEL we lose our ability to keep and maintain Swing ratios for Power of Carrier in watts to Effective Peak Envelope Power (we are not doing a dissertation on PEP - just want to see good power delivery in known analog meters - knowing the limitations of metering systems - nothing more).

If your network (I cannot stress this enough) is tuned right - the REF power is simply power the Network cant process and the amps' "pills" are combining their SATURATION level into a complex power curve of reflected power returned thru the network into the SWR meter - this power is being returned to your radio.

This is where it gets complicated, because we are dealing with a reactive load - the antenna - and its' own SWR issue on the line - this we know. (It's what we tuned to lowest SWR) But we need to know the REFECTED power the antenna can't use - being returned into the amp - that is combining with the power flowing into the Network from your Radio. (We can't use this, but to know HOW the amp REACTS to Input power while you have REFLECTED power from the antenna trying to be absorbed into the AMP) Hey - the AMP is busy - and if we add too much more power - the AMP REFLECTS more and more back - its like a Busy signal when you call someone - only you can't leave a voice mail - you have to wait for the line to clear before you make a connection - similar process...

We want that FWD power level - the best power transfer we can do, before REF power overtakes and we lose our ability to do work (FWD) (Torque) because we're wasting effort on trying to make the system ABSORB more power (REF) (RPM) the RPM's go up but all we do is just make more noise and heat and accomplish nothing more - we can't add more Torque - we lose efficiency.

So do some experiments - and for anyone else still reading this - (Thank you) - just see what your CAL knob does or how much rotation it needs to "meet SET" for your AT-6666 power output - to go into the AMP before the
REF power washes out the effort.

Power up the Amp...
Tune your antenna for the amp...
Put the SWR meter in line at the radio side...
Start on low power - Set Meter to FWD - Turn Cal all the way down - Key up to SET - note KNOB setting.-Switch to REF - note reading (write these down!)
Go up one power level
Set Meter to FWD - Turn Cal all the way down - Key up to SET - Note KNOB Reading - Switch to REF - Note Reading (Write This Down)
Repeat this process for the power levels...

I know you have to turn a knob , but this level of tuning is what helps me know just how many watts you can send before REF gets too much in the way.

Gotta' get to bed...

Let me know how this goes...

 

[530]

The simple way?

(Gosh Darn It...)

Run your radio as if you are going into typical antenna - 50 ohm load - you want 3watts at least to keep the Pills going forward...(I'm referring to producing power...)

Unless I see something over my screen showing the "innards" of your amp - we can only speculate...

Because of what I've dealt with before...

IF you use a typical setup - you need 4 watts to 16 PEP - that is the typical CB radio does yes, but that is just to "Hold it up" and keep producing power.

Remember the bigger issue is with SWR. At least by what you saw.

So I'll kinda need the "low-down" on what has been done to the amp to help you...

So while you're at it, I need to you go back to that setup - once you have your antenna all tuned up? And you got the AMP loading into the Antenna - and you're ok with the SWR? (Hope 1.5 or less on this please)

Because then I'll need you to set up the SWR meter in-line TO THE AMP from the AT-6666.
Only this time - you only need the FWD setting readings - to get to Top of Calibrate on the meter face...

View attachment 35380​

There is a trick to this...
I need to know, or what I'm looking for from you - so we get the reporting right...
How much power is being ABSORBED into the AMP - per power level setting...
Yes, there is an ideal "level" of power before the REF (your reflected power) starts to go up...
If the NETWORK was tuned right - there will be a "Window" where the amp will accept the highest level of power from the Radio - this you can see in the FWD setting and you compare it to REF...

This has to be done in steps...

What your FWD Meter setting CAL knob is doing - for the various power levels you can set your AT-6666
How far do you have to turn your CAL knob to meet "SET"? Naturally - you'd be seeing the CAL knob ACTUALLY GET TURNED DOWN once your power output from the radio goes up...True?
Well, that's Obvious....

View attachment 35381
He's watching ... you know...
​

Ok, you also need to know your REF power at that particular POWER IN setting - so we can see how much power CANNOT be used - So it is important to KNOW How Much POWER the Network needs - before we send too much power in and it starts REFLECTING MORE than what it uses - back...

So your know...

• You will always have REF power this is a loss to your effort to transfer power into a less than ideal load.
  • (So, yes, tune the ANTENNA for your LOWEST SWR BETWEEN THE AMP AND THE ANTENNA FIRST - so we don't add more complexity to the situation of POWER and where it's going)
• The Power going into the amp will approach a point of "no return on investment" NROI - the more power you put in - you don't get out - unless you want more heat.
  • This factor requires TWO meters, one at the Input and the other monitoring the Output. It would be nice to have, but not necessary at this point.
  • If you know of a Dynamometer - you see RPM versus Torque - we're looking for this same effect only we are looking at the ratio of FWD in to REF back to the Radio. Torque produces an ability to do work - RPM is the Rate of work - we are looking to see simple Carrier power and Audio "swing" ratio as we go up in power - pretty soon we will flat top out and not get any more swing - but we can still provide more carrier - IT IS AT THIS LEVEL we lose our ability to keep and maintain Swing ratios for Power of Carrier in watts to Effective Peak Envelope Power (we are not doing a dissertation on PEP - just want to see good power delivery in known analog meters - knowing the limitations of metering systems - nothing more).

If your network (I cannot stress this enough) is tuned right - the REF power is simply power the Network cant process and the amps' "pills" are combining their SATURATION level into a complex power curve of reflected power returned thru the network into the SWR meter - this power is being returned to your radio.

This is where it gets complicated, because we are dealing with a reactive load - the antenna - and its' own SWR issue on the line - this we know. (It's what we tuned to lowest SWR) But we need to know the REFECTED power the antenna can't use - being returned into the amp - that is combining with the power flowing into the Network from your Radio. (We can't use this, but to know HOW the amp REACTS to Input power while you have REFLECTED power from the antenna trying to be absorbed into the AMP) Hey - the AMP is busy - and if we add too much more power - the AMP REFLECTS more and more back - its like a Busy signal when you call someone - only you can't leave a voice mail - you have to wait for the line to clear before you make a connection - similar process...

We want that FWD power level - the best power transfer we can do, before REF power overtakes and we lose our ability to do work (FWD) (Torque) because we're wasting effort on trying to make the system ABSORB more power (REF) (RPM) the RPM's go up but all we do is just make more noise and heat and accomplish nothing more - we can't add more Torque - we lose efficiency.

So do some experiments - and for anyone else still reading this - (Thank you) - just see what your CAL knob does or how much rotation it needs to "meet SET" for your AT-6666 power output - to go into the AMP before the
REF power washes out the effort.

Tune your antenna for the amp...
Put the SWR meter in line at the radio side...
Start on low power - Set Meter to FWD - Turn Cal all the way down - Key up to SET - note KNOB setting.-Switch to REF - note reading (write these down!)
Go up one power level
Set Meter to FWD - Turn Cal all the way down - Key up to SET - Note KNOB Reading - Switch to REF - Note Reading (Write This Down)
Repeat this process for the power levels...

I know you have to turn a knob , but this level of tuning is what helps me know just how many watts you can send before REF gets too much in the way.

Gotta' get to bed...

Let me know how this goes...

Will do, and thank you. May take a bit I don't have a meter with calibration. But I will try this. I will also keep it down for now because its the way I drove my TS500DX was 20 watts PEP. I am still not understand how it can be ok to run 2879s that high when the toshibas only suggest 10 watts max pep and I read 5 will get you the 100 watts output. The only thing I read that some just use buffers but I dont think that applys here. So I am still confused. Its like the old overdriven 667Vs with the 2290. But I had one and it lasted many years. I really do feel if i drive it like he showed in the video these transistors won't last long, but I am no way close to being any kind of tech and have read probably 1000s of searched posts. Probably would have been easier just learning it from the beginning. His site says "400 4 hg 2879, Class C bias, fan cooled. Max amp draw 110a, install recommended with 4ga wire and 125a fuse. Max input carrier of 10 w or 200w max carrier from amp. Max peak input 200w."
So I will get that meter. May take a few days, busy with real life here LOL. Just got off temp disability and back to work this week. I will definitely test what you said and report back at some time. I do appreciate the learning experience. It is borderline to hard to understand for me but good so far LOL. Thanks again.

 

[Handy Andy]

Don't worry so much about "calibration" I just want you to know what you're seeing...

I ran out of time last night to do this up, but this morning I got out some older notes that were from days of when I had a different life - seems like eons ago - but I did this to help me "plot" out my antennas that I used to obtain or "hit" a repeater from a distance - kinda' like a "Field Day" - but using different antennas - loading and length - to make the best "quieting" to get the repeater to respond and have a QSO.

Back then I was more of a WX fan and used Ham Radio "nets" to report for their efforts.

But that was a long time ago...

These charts were my notes on, are "how far back CAL was set" compared to "Reflected at the wattage I'm putting into it" ...this got applied later in life as a means to show drivers how to properly set the power levels in your Co-Phase system in your trucks - so you don't keep coming back here asking us to drop-in another amp or fix the finals in a radio that they blew up from getting careless.

This is similar but you are looking at the AMP as the load your putting power into - and you're then observing and reporting "ok I put this much in - this happens - this comes back...."

So yes, it looks backwards, but the results are used to attain an idea of how safe I can be when I'm trying to use as much power as possible into a known system, before I lose control of it and possible damage.​

Yes, I said Damage - I've lost power modules in the 2M radios I used - so this became a method to attain a transfer to power delivery chart to help me find a spot for the antenna - and radio pushing power into it, to work together - using only two SWR meters and were separated - from inside to outside.

I already had a Known reference - 50 ohms - I just needed to see Watts and which way they were traveling.

SWR meters are considered DIRECTIONAL Wattmeters - they can show power flowing in two directions - more-so they are SUMMATION too - meaning if power BOUNCES back from REFLECTED BACK (like a ripple of water from a stone dropped into a quiet pond) it then ADDS to the Forward power trying to re-approach (re-enter) the antenna - same for Reflected - the entire system can be measured as a rise not just in power but in which direction it is going.

So if you increment Power into the system - you look at CAL knob position rotation BACK from initial setting ( Starts when you have enough power in wattage to key and hold the amp up to operate) then look at REF - if the amp just needs some simple tuning - it will be consistent - an OFF-SWR reading that doesn't change. As you raise power - the CAL knob known change in rotation you need to set it to, to bring it back to SET - ATTENUATES REF power reading in proper proportions - so again - if it stays consistenly a "set" value - the amp is the part that needs tuning throughout the power range of input into the amp.

• When things go wrong is when the SWR REF climbs suddenly as you add power - this means the AMP can't handle the extra power - it's losing control - beyond a set limit - this is your critical point where if you keep adding power, Damage can occur.
• This is a reciprocal event - the antenna is reactive too. This will affect how the AMP responds in this test, it is an EXPECTED result - we are just looking as how much power we can add into the amp before it goes critical. We look at REFLECTED power that can't be used by the amp as this known limit.

Note those KNEE plot points - that is where I would have to stop adding power before I could damage the system from a bad reflection back to the radio and lose that power module.

The farther the KNEE is up (or down and to the left in the above graph) in the power level (the diagonal) means the ability to absorb and use the power I'm sending to the antenna to radiate - I then listened for the Repeater response either thru QSO or Repeater Test mode - to determine if I can attain and hold contact under certain conditions and the antenna used for this test. The responses were the feedback for the results of the test - good / bad - type of scenario. Terrain plays a role in this as well as WX conditions so the above again is a relative plot to help me use the best antenna length design for the vehicles this test was done on.

I attached a simple JPG file to help you - you can print it or just put it on your PC and plot that way - just save a copy for your use to return to if you need to "restore" and do over. You can edit the file in simple PAINT program and modify as you wish, just use it to help you determine the problems in your system so you can visualize the results and work accordingly to fix them.

 

[530]

Don't worry so much about "calibration" I just want you to know what you're seeing...

I ran out of time last night to do this up, but this morning I got out some older notes that were from days of when I had a different life - seems like eons ago - but I did this to help me "plot" out my antennas that I used to obtain or "hit" a repeater from a distance - kinda' like a "Field Day" - but using different antennas - loading and length - to make the best "quieting" to get the repeater to respond and have a QSO.

Back then I was more of a WX fan and used Ham Radio "nets" to report for their efforts.

But that was a long time ago...

These charts were my notes on, are "how far back CAL was set" compared to "Reflected at the wattage I'm putting into it" ...this got applied later in life as a means to show drivers how to properly set the power levels in your Co-Phase system in your trucks - so you don't keep coming back here asking us to drop-in another amp or fix the finals in a radio that they blew up from getting careless.

This is similar but you are looking at the AMP as the load your putting power into - and you're then observing and reporting "ok I put this much in - this happens - this comes back...."

View attachment 35395

So yes, it looks backwards, but the results are used to attain an idea of how safe I can be when I'm trying to use as much power as possible into a known system, before I lose control of it and possible damage.​

Yes, I said Damage - I've lost power modules in the 2M radios I used - so this became a method to attain a transfer to power delivery chart to help me find a spot for the antenna - and radio pushing power into it, to work together - using only two SWR meters and were separated - from inside to outside.

I already had a Known reference - 50 ohms - I just needed to see Watts and which way they were traveling.

SWR meters are considered DIRECTIONAL Wattmeters - they can show power flowing in two directions - more-so they are SUMMATION too - meaning if power BOUNCES back from REFLECTED BACK (like a ripple of water from a stone dropped into a quiet pond) it then ADDS to the Forward power trying to re-approach (re-enter) the antenna - same for Reflected - the entire system can be measured as a rise not just in power but in which direction it is going.

So if you increment Power into the system - you look at CAL knob position rotation BACK from initial setting ( Starts when you have enough power in wattage to key and hold the amp up to operate) then look at REF - if the amp just needs some simple tuning - it will be consistent - an OFF-SWR reading that doesn't change. As you raise power - the CAL knob known change in rotation you need to set it to, to bring it back to SET - ATTENUATES REF power reading in proper proportions - so again - if it stays consistenly a "set" value - the amp is the part that needs tuning throughout the power range of input into the amp.

• When things go wrong is when the SWR REF climbs suddenly as you add power - this means the AMP can't handle the extra power - it's losing control - beyond a set limit - this is your critical point where if you keep adding power, Damage can occur.
• This is a reciprocal event - the antenna is reactive too. This will affect how the AMP responds in this test, it is an EXPECTED result - we are just looking as how much power we can add into the amp before it goes critical. We look at REFLECTED power that can't be used by the amp as this known limit.

Note those KNEE plot points - that is where I would have to stop adding power before I could damage the system from a bad reflection back to the radio and lose that power module.

The farther the KNEE is up (or down and to the left in the above graph) in the power level (the diagonal) means the ability to absorb and use the power I'm sending to the antenna to radiate - I then listened for the Repeater response either thru QSO or Repeater Test mode - to determine if I can attain and hold contact under certain conditions and the antenna used for this test. The responses were the feedback for the results of the test - good / bad - type of scenario. Terrain plays a role in this as well as WX conditions so the above again is a relative plot to help me use the best antenna length design for the vehicles this test was done on.

I attached a simple JPG file to help you - you can print it or just put it on your PC and plot that way - just save a copy for your use to return to if you need to "restore" and do over. You can edit the file in simple PAINT program and modify as you wish, just use it to help you determine the problems in your system so you can visualize the results and work accordingly to fix them.

Ok thank you very much. Getting a little harder for me with the graph LOL, not very good at it but I will see what I can do. Still grasping all this other new info as I am far from any technical knowledge. When I do have time I will enjoy trying this though. Thanks again.

 

[Handy Andy]

Don't worry about the Graph, just a paper for plotting points...

(I went back over my notes, I drew the plots wrong - I'll update that here shortly...)

Just keep track of how the SWR does as you adjust power as you try to find a "Sweet Spot" it's when it climbs as you tune.

For YOU

• - Just focus on providing LOW SWR for the antenna and AMP
• - What about SWR issues for the - radio?
  • Try not to worry about High SWR - you haven't got there yet so Not so much
  • - the AT's I believe has some type ANT SWR alert as well as seen that they have a pretty hefty network - they do take some abuse. You turn down the power on it (radio) when you're not sure....

Just Remember - the ANYTONE's aren't Type-Certified for Wheel Chock status just yet...

 

[2NC995]

Yes....THIS:

• - Just focus on providing LOW SWR for the antenna and AMP

• - What about SWR issues for the - radio?
  • Try not to worry about High SWR - you haven't got there yet so Not so much
  • - the AT's I believe has some type ANT SWR alert as well as seen that they have a pretty hefty network - they do take some abuse. You turn down the power on it (radio) when you're not sure....

 

[Handy Andy]

I saw (read) something earlier and then looking over my notes...I wanted to ask this...because no one else seemed to "catch" your "SWR VALUE" that kept showing up...

I am match tuning swr on 1 and 40. I have a 6666 and a 400HD amp. I have a meter in the radio and one after my amp. I was told to tune from the after amp swr meter with the amp and radio on low, They are reading the opposite swr from each other. Hard for me to tune to match exact. Both are still off and not matched but I tried to make them off matched the same. I can't get either to match exact or one meter goes way off than the other if i try tuning either way. My swr is showing about a 1.7 on channel 1 and around 1.3 on channel 40 at the radio and about that exact opposite after the amp. Channel 19 is showing 1.5 on both(the radio blinks 1.5 1.4, meter showing 1.5). First time I actually tuned using a meter after the amp. Does any of this this even sound normal? Thanks in advance.

Did you buy the amp used?

I mean it's not a big deal, or it could be - depending on what or how the amp was used BEFORE you got this one.

I'm referring to the consistent 1 : 1.4 ~1.5 SWR reading...

Why? Well, if the amp was used for a Trucker that used it for Co-Phased systems (read dually - antennas) - they appear as 72~75 ohms of impedance - it's not impossible to think that maybe the output network needs to be returned to make it appear as 50 ohms. In my experience SWR of 1 : 1.7 on down to 1 : 1.5 may indicate Coax impedance problems - a simple "wrong coax" for "right antenna" system.

I think that may be your SWR problem - not a big one but It is a power reflection issue and it may be from a output network set up for a Co-Phasing harness that uses 72~75 ohm (RG-59) versus the RG-8/58 stuff seen on SINGLE antenna systems.

 

[530]

I saw (read) something earlier and then looking over my notes...I wanted to ask this...because no one else seemed to "catch" your "SWR VALUE" that kept showing up...



Did you buy the amp used?

I mean it's not a big deal, or it could be - depending on what or how the amp was used BEFORE you got this one.

I'm referring to the consistent 1 : 1.4 ~1.5 SWR reading...

Why? Well, if the amp was used for a Trucker that used it for Co-Phased systems (read dually - antennas) - they appear as 72~75 ohms of impedance - it's not impossible to think that maybe the output network needs to be returned to make it appear as 50 ohms. In my experience SWR of 1 : 1.7 on down to 1 : 1.5 may indicate Coax impedance problems - a simple "wrong coax" for "right antenna" system.

I think that may be your SWR problem - not a big one but It is a power reflection issue and it may be from a output network set up for a Co-Phasing harness that uses 72~75 ohm (RG-59) versus the RG-8/58 stuff seen on SINGLE antenna systems.

OK not used, brand new. I sent a link for one exactly like mine in a previuos post. Its Carl from the old XForce amps, if you know him. I am using two 15ft lmr400UF coax on a breedlove puck mount center of my jeeps roof. I went out and tried tuning today with a litlle more insight, and time. Got the swr almost perfectly matched on 1 and 40 with amp on, low radio power, down to 1.2 on both 1 and 40 and 1.0 on 1 and 40 with the amp off. I could do a little better on my Skipshooter cause it was a hair off still but I was hungry LOL. When I turn the power up on the radio now swr slowly raises to about 1.4(1) 1.5(40) on the amp swr meter until about 1/2 radio power. From there slowly raises and at full radio power its 1.5 on 1, 1.7 on 40, 1.4 on 19. This was with a 6ft Skipshooter. My Predator K-27-1 did a little better but it looks like i got it closer to exact. Didn't have time for my 108 in Whip.

 

[Handy Andy]

Man! You are killin' it!

SWR looks a lot better today...

I have a lot less to worry about...

You been foolin' us - you're nailing it!

I just want you to enjoy this for what it means to you.

It's not a job, nor chores around the house - this is your time to have fun!

Nice job - Good work!

...now quit laughing at us and get out there and have some fun...

 

[2NC995]

Yeah, you don't need to do anything with that!

 

[ForestRunner98]

Your set!!!

 

[530]

Yes, thank you. Still going to try the REF thing LOL and see how that goes just for a learning experience when I get time. Thank you all!