Predator 10k issues

[BIGHOG]

So I got close to finishing the Duramax install yesterday. Stryker 447, 15' LMR 240 to Fatboy 2x8, 18' LMR 400 to Breedlove puck mounted on roof of cab. Problem is I can only get 1.5 across the band with the 10k, and get 1.1 across the band with my 108ss whip. I plan on doing plenty of bonding for running the power but don't see why one antenna would show better result than the other? What now?

[Deleted User 14541]

What is the length of the lower shaft on the 10k? Anything shorter than 17" didn't tune very well on my truck.

[BIGHOG]

I will have to check when I get home. Pretty sure it's it's atleast 17".

[MDYoungblood]

Really 1.5:1 isn't bad, like 543 said it's probably because of the shaft and closeness of the coil to the roof, it is a capacitance thing. I've also been reading on other forums that they are having the same problem using the Breedlove Puck, one changed to a different make puck and the problem went away.

3's

Greg

[BIGHOG]

Really 1.5:1 isn't bad, like 543 said it's probably because of the shaft and closeness of the coil to the roof, it is a capacitance thing. I've also been reading on other forums that they are having the same problem using the Breedlove Puck, one changed to a different make puck and the problem went away.

3's

Greg

Well that's a bummer. I ran a Gunny puck on my S10 with good results. Everybody always praises the Breedlove stuff so I figured I would give it a try...... I agree, 1.5 is not that bad but, would you run a 2x8 threw it? After the 108 is completely flat (barely even moves the needle), its hard to just accept that 1.5 is all I can do with the 10k

[MDYoungblood]

In all actuality 1.5 is 50 ohms. Is the SWR 1.5 with the amp inline? I myself would run it but I do SSB and am not a long winded modulator. I would call or email Kale at Predator 10k, see what he thinks and maybe get a longer shaft.

3's

Greg

[Deleted User 14541]

Really 1.5:1 isn't bad, like 543 said it's probably because of the shaft and closeness of the coil to the roof, it is a capacitance thing. I've also been reading on other forums that they are having the same problem using the Breedlove Puck, one changed to a different make puck and the problem went away.

3's

Greg

That's odd. Was it the breedlove puck or one of his lighter mounts? I didn't notice any difference going from the breedlove to the xforce puck. The only reason I removed it was because I thought the brass center was trying to spin out. Once I removed it I found out the brass insert is threaded and was just loose.

The one issue I can see with the breedlove is if the person didn't sand the underside of the roof to bare metal and use some dielectric grease or noalox. Unlike the dave style puck there is a plastic insulator on the bottom of the breedlove so the ground is made through the backing plate and bolts.

In all actuality 1.5 is 50 ohms. Is the SWR 1.5 with the amp inline? I myself would run it but I do SSB and am not a long winded modulator. I would call or email Kale at Predator 10k, see what he thinks and maybe get a longer shaft.

3's

Greg

1.5 is more like 75 ohms if we were dealing with a nonreactive load. a 1.5 swr is a very good match but if the guy is wanting to run the amplifier hard he needs as good of a match as possible to make the pills live as long as possible.

[jessejamesdallas]

Which Predator did you get? I've found some of the 10k's don't tune as low as orhers, and shafts shorter than 17" (like already pointed out) just don't like roof mounts on some vehicles...

If you do have a 17" shaft, then your only option maybe to get a 22" shaft ( which I don't recommend on the roof) or try a different coil.

[BIGHOG]

I did not sand the underside of the roof to bare metal....... Should I pull it back apart and do that? Still doesn't explain why the 108 will tune 1.1 or less. Unless it's just the nature of the 10k?

[MDYoungblood]

Which Predator did you get? I've found some of the 10k's don't tune as low as others, and shafts shorter than 17" (like already pointed out) just don't like roof mounts on some vehicles...

If you do have a 17" shaft, then your only option maybe to get a 22" shaft ( which I don't recommend on the roof) or try a different coil.

All the "Burbs" run the 22" shaft here with good results, I agree putting the coil up off the roof that high makes it easier to knock the antennas off.

In all actuality 1.5 is 50 ohms. Is the SWR 1.5 with the amp inline? I myself would run it but I do SSB and am not a long winded modulator. I would call or email Kale at Predator 10k, see what he thinks and maybe get a longer shaft.

3's

Greg

1.5 is more like 75 ohms if we were dealing with a nonreactive load. a 1.5 SWR is a very good match but if the guy is wanting to run the amplifier hard he needs as good of a match as possible to make the pills live as long as possible.

Yep, brain f**t first thing this morning.

I have never installed a Breedlove's puck so I can't say yea or nae, only went from what I've read, I prefer 626's puck or mount.

3's

Greg

[BIGHOG]

Now I'm thinking I should have skipped the puck and just thrown a 5000 up there. Not going to let this thing woop me. Just hope the info and experience keeps flowing in. You guys are awesome help. That's why I love CBRT. Lots of knowledge here. Keep it coming guys. The 2nd alternator is going on this week so I've got to get this thing figured out!

[jessejamesdallas]

Which Predator did you get? I've found some of the 10k's don't tune as low as others, and shafts shorter than 17" (like already pointed out) just don't like roof mounts on some vehicles...

If you do have a 17" shaft, then your only option maybe to get a 22" shaft ( which I don't recommend on the roof) or try a different coil.

All the "Burbs" run the 22" shaft here with good results, I agree putting the coil up off the roof that high makes it easier to knock the antennas off.

In all actuality 1.5 is 50 ohms. Is the SWR 1.5 with the amp inline? I myself would run it but I do SSB and am not a long winded modulator. I would call or email Kale at Predator 10k, see what he thinks and maybe get a longer shaft.

3's

Greg

1.5 is more like 75 ohms if we were dealing with a nonreactive load. a 1.5 SWR is a very good match but if the guy is wanting to run the amplifier hard he needs as good of a match as possible to make the pills live as long as possible.

Yep, brain f**t first thing this morning.

I have never installed a Breedlove's puck so I can't say yea or nae, only went from what I've read, I prefer 626's puck or mount.

3's

Greg

Oh you can run the 10K on the roof with a 22" even a 27" shaft if you want...I use to run 27" shaft-single coil 10K's on the roof of my burb also....

I also have a large collection of broken shafts too...

[BIGHOG]

Can I order just the longer shaft? Think I should pull it back apart and take the paint off the underside of the cab? (Rally hate to but I will if necessary. Its got to be something simple..... A Wilson mag mount came in at 1.2 in that location. So why would going to a puck and doing it right give me worse results? I think I need more knowledge about antenna matching maybe?

-- August 08 2016 --

I di check SWR on the other bands as well. Maybe this is useful info?

A band ch 1 3.0 ch 40 2.5

D band ch1 1.6 ch 40 1.4

H band ch1 2.4 ch 40 3.1

[jessejamesdallas]

The Predators are broad banded enough to get by on channels either side of the regular 40 CB-(11 meter) channels, but that's about it. Best to tune the antenna for the 40 channels you will be using the most.

You can order the lower shaft "yes". Most places that sell the Predators also sell replacement parts... If the place you purchased yours from don't, then just do some Googling.

Since you say the other antennas all seem to tune fine on your puck, I doubt taking it off and sanding the paint down is going to make any difference what so ever.

[MDYoungblood]

X2 with what JJD said. I think it could be location of the puck as well. Toward the rear of the cab (think your install is a pickup) the antenna is not seeing (just an expression) the ground plane of the vehicle in one plane (the drop to the bed). You can make a quick test with a length of wire and alligator clips, take the wire and one clip at the back of the bed (clip it to the pocket on the bed rail), take it around the puck base (not the insulated part), bare the wire there (making contact with the base of the puck) and back down to the other pocket and clip it. Check your SWR, I'll bet it changes for the better. If you have the puck in the center of the roof this wouldn't change much.

3's

Greg

[BIGHOG]

Yes, this is a crew cab long bed dually. So it sounds by what your saying is.... when I start to bond the truck (which I'm doing anyway) ...... The readings should come down since the truck will work together a more complete ground plane?

[MDYoungblood]

Bonding everything always helps, found with my pickup the bed did not have a suitable ground, the straps had either been removed or just fallen off. Hood, doors, and tailgate hinges (locks too) have plastic bushings that act as insulators not to mention the rubber seals. I think you'll see an improvement with every strap installed.
I only have a 2 pill now but ran a 8 pill with just one battery and a 210amp alternator, too many issues with the vehicle's electronics and the one beside me on the interstate to keep it.

3's

Greg

[BIGHOG]

Bonding everything always helps, found with my pickup the bed did not have a suitable ground, the straps had either been removed or just fallen off. Hood, doors, and tailgate hinges (locks too) have plastic bushings that act as insulators not to mention the rubber seals. I think you'll see an improvement with every strap installed.
I only have a 2 pill now but ran a 8 pill with just one battery and a 210amp alternator, too many issues with the vehicle's electronics and the one beside me on the interstate to keep it.

3's

Greg

I know about the electronics issue far too well. All of this equipment was in my 99 S 10 at one time. That truck had everything strapped and I still had issues from time to time. The dually will have dual 145's. Better idle amperage output (about 160a at idle and almost 300a at cruising speed). Should make a killer setup of I can get it all working together!

[The DB]

In all actuality 1.5 is 50 ohms. Is the SWR 1.5 with the amp inline? I myself would run it but I do SSB and am not a long winded modulator. I would call or email Kale at Predator 10k, see what he thinks and maybe get a longer shaft.

3's

Greg

1.5 is more like 75 ohms if we were dealing with a nonreactive load. a 1.5 swr is a very good match but if the guy is wanting to run the amplifier hard he needs as good of a match as possible to make the pills live as long as possible.

In addition to 75 ohms, 1.5:1 SWR can also be a 33.3 ohm resonant load. Remember SWR goes up as R goes both up or down from a 50 ohm resonant load, its not a one direction thing.


The DB

[Deleted User 14541]

I did not sand the underside of the roof to bare metal....... Should I pull it back apart and do that? Still doesn't explain why the 108 will tune 1.1 or less. Unless it's just the nature of the 10k?

I can't say if you will or won't see a change but I would pull it apart and do it right. Don't forget the noalox or something to prevent corrosion. If the 10k doesn't work put put a 6 or 7 ft skipshooter up there. My 10k is collecting dust in the garage. Not saying it's a bad antenna by any means.

Now I'm thinking I should have skipped the puck and just thrown a 5000 up there. Not going to let this thing woop me. Just hope the info and experience keeps flowing in. You guys are awesome help. That's why I love CBRT. Lots of knowledge here. Keep it coming guys. The 2nd alternator is going on this week so I've got to get this thing figured out!

You'll be glad you installed the puck. If you're going to the trouble of installing a second alternator I wouldn't skimp on the mount.

In all actuality 1.5 is 50 ohms. Is the SWR 1.5 with the amp inline? I myself would run it but I do SSB and am not a long winded modulator. I would call or email Kale at Predator 10k, see what he thinks and maybe get a longer shaft.

3's

Greg

1.5 is more like 75 ohms if we were dealing with a nonreactive load. a 1.5 swr is a very good match but if the guy is wanting to run the amplifier hard he needs as good of a match as possible to make the pills live as long as possible.

In addition to 75 ohms, 1.5:1 SWR can also be a 33.3 ohm resonant load. Remember SWR goes up as R goes both up or down from a 50 ohm resonant load, its not a one direction thing.


The DB

I couldn't remember 33.3 this morning and it was too lazy to do the math.

[BIGHOG]

It is a 17 inch Predator 10-K. The Breedlove puck has a two inch riser on it. I'm wondering if that is having a negative effect on the SWR. The last puck I ran the 10K on did not have a riser?

[jessejamesdallas]

It is a 17 inch Predator 10-K. The Breedlove puck has a two inch riser on it. I'm wondering if that is having a negative effect on the SWR. The last puck I ran the 10K on did not have a riser?

doubt it...if anything I would think it would be a benifit since longer shafts on the 10K's usually tune better.

[BIGHOG]

Wondering if I should think about investing in an analyzer? At this point that would be the only tool to help me get past this right?

[MDYoungblood]

It is a 17 inch Predator 10-K. The Breedlove puck has a two inch riser on it. I'm wondering if that is having a negative effect on the SWR. The last puck I ran the 10K on did not have a riser?

Is the stinger/whip bottomed out? Have you cut any off of it yet or when it was on the other vehicle? 2 inches adds to the overall length of the antenna, that is a lot when it comes to tuning 27mhz. If the SWR increases with the stinger lengthening and decreases when shortened it might need to be cut. If you cut it (1/4" at a time) and don't see an improvement in SWR stop cutting it.

3's

Greg

[BIGHOG]

It is a 17 inch Predator 10-K. The Breedlove puck has a two inch riser on it. I'm wondering if that is having a negative effect on the SWR. The last puck I ran the 10K on did not have a riser?

Is the stinger/whip bottomed out? Have you cut any off of it yet or when it was on the other vehicle? 2 inches adds to the overall length of the antenna, that is a lot when it comes to tuning 27mhz. If the SWR increases with the stinger lengthening and decreases when shortened it might need to be cut. If you cut it (1/4" at a time) and don't see an improvement in SWR stop cutting it.

3's

Greg

Yes the stinger was cut when it was on the S10. I thought that when you equaled out the SWR (which is 1.5 1-40 currently) that those results were what you were stuck with as far as stinger up and down was concerned. Is this not correct?