Frustrating POTA Activation today

[WRYZ926]

11 minutes ago, TNFrank said:

I'm going to order the Radioditty HP-009 because I like the way the coil is enclosed so it's protected from the elements. It costs a bit more but I think it'll be worth the extra money in the long run.

The extra $15 for the HF-009 is worth it. Radioddity has their bundle price of $149

https://www.radioddity.com/products/radioddity-hf-009

[WRYS709]

Good Choice! 

[Northcutt114]

OK, so...the head scratching continues.

New antenna came in today. Still won't tune below 4.0 SWR on 10m. No coil, just the four sections of poles with the whip on top attached and extended to roughly 8' 3" total length...which, if my math is correct, is roughly a 1/4 wavelength on 10m. Wouldn't tune below a 4.0.

THEN...

I put the coil on, ran the slider up to the top, extending the whip all the way out and it tuned 40m just fine. Down to 1.0. I then slid the coil down to the bottom and it tuned 20m just fine. Down to 1.0. Perfect. I then tried tuning it that way on 10m and it brought SWR down to 2.0.

So I'm at a loss. This exact antenna used to INSTANTLY tune to 1.0 on 10m. Now it won't tune it at all...but will tune 40 and 20m just fine. I tried tuning it with less sections of the pole, nothing. With the antenna as long as I could make it,  it would only tune 10m to 2.0 SWR. Which doesn't make sense because a 1/4 wave on 10m should be the shortest of all.

Any thoughts?

 

[SteveShannon]

4 hours ago, Northcutt114 said:

OK, so...the head scratching continues.

New antenna came in today. Still won't tune below 4.0 SWR on 10m. No coil, just the four sections of poles with the whip on top attached and extended to roughly 8' 3" total length...which, if my math is correct, is roughly a 1/4 wavelength on 10m. Wouldn't tune below a 4.0.

THEN...

I put the coil on, ran the slider up to the top, extending the whip all the way out and it tuned 40m just fine. Down to 1.0. I then slid the coil down to the bottom and it tuned 20m just fine. Down to 1.0. Perfect. I then tried tuning it that way on 10m and it brought SWR down to 2.0.

So I'm at a loss. This exact antenna used to INSTANTLY tune to 1.0 on 10m. Now it won't tune it at all...but will tune 40 and 20m just fine. I tried tuning it with less sections of the pole, nothing. With the antenna as long as I could make it,  it would only tune 10m to 2.0 SWR. Which doesn't make sense because a 1/4 wave on 10m should be the shortest of all.

Any thoughts?

 

Either sweep it with your G90 or get an antenna analyzer so you can really see where the dip is between 12 and 9 meters and what the effect is on the antenna of changing the length. 

[Northcutt114]

11 hours ago, SteveShannon said:

Either sweep it with your G90 or get an antenna analyzer so you can really see where the dip is between 12 and 9 meters and what the effect is on the antenna of changing the length. 

When you say "sweep it," what do you mean? Just "check the SWR at various frequencies?" I think that's what you mean, just wanted to be sure.

[SteveShannon]

41 minutes ago, Northcutt114 said:

When you say "sweep it," what do you mean? Just "check the SWR at various frequencies?" I think that's what you mean, just wanted to be sure.

The G90 (my understanding without owning it) has the ability to sweep (do an SWR scan between one frequency and another) and display the results on-screen similar to an antenna analyzer.  I’ll look for a YouTube video that demonstrates the process. 

[SteveShannon]

Here you go:

 

[SteveShannon]

I wonder if this is linked to the issue you’re experiencing with a sudden SWR reading:

https://youtu.be/MQacBNH0eXg?si=LmHEx9cnN7cfeI8i

[Northcutt114]

3 hours ago, SteveShannon said:

The G90 (my understanding without owning it) has the ability to sweep (do an SWR scan between one frequency and another) and display the results on-screen similar to an antenna analyzer.  I’ll look for a YouTube video that demonstrates the process. 

Yeah, ok, so just scan prior to tuning. That's what I was doing. If I get home before dark, I'll try again. And thanks for the "operating split" video. But nope, that's not the issue. I'm not operating split. I said that earlier but it was easily missed, I'm sure. I appreciate the help!

 

Just to test my theory again, I hooked the radio up to a dummy load and it instantly tuned to 1.0 on every band. So the radio is tuning an EFHW on all bands and this 1/4 wave vertical on 40 and 20....but not 10. I'm stumped. Especially in light of the fact that it did tune it just fine a week or so ago.

 

[Northcutt114]

I decided to shelve the JCP 12 for awhile. I strung my 40m EFHW in an inverted V this afternoon to christen my voyage on 20m. I haven't even trimmed to length. I think it's 70' at the moment? So, not really resonant, but closeish. Highest point of the V is 31' off the deck. Balun is 15' and the end of the wire was maybe 8'? So...hasty, right?

I hunted 11 stations and made QSO's with 9 or them. I couldn't get through the pile up on 2 of them with my QRP rig so I left. I did get a 41 report from Colorado, but all other stations were above 55. So I'm getting out, the box is working, and the tuner is tuning.

Thoughts on 20m vs 10m. I was able to hear a lot more of the conversations. on 10m, I found myself hearing a lot of one sided conversations...and while I did on 20, too, there were less of them. I could hear and contact stations closer in. Two in FL and I'm in GA. I beginning to see why 20m is so popular on POTA. It's not blasting you out all over the place like 10m is.

Also, I heard a station in Nambia today! He was hunting the station I was hunting. He was just above the noise, but I heard him and it knocked the socks off the guy that was activating. That's definitely a long way away.

 

[TNFrank]

The day started out kind of slow. I'm running an EFHW set up for 20M(33'~ 18 gauge wire) that I tuned to less than 1.3:1 using my SWR meter. I ended up moving it to a different orientation and gave the 10M Band time to come around and ended up getting some QSO's including my last one in Hawaii that was a 5/6 here and I was a 5/5 there. All in all it was a pretty good day.

[Northcutt114]

14 hours ago, TNFrank said:

... ended up getting some QSO's including my last one in Hawaii that was a 5/6 here and I was a 5/5 there. All in all it was a pretty good day.

It's interesting to me that you've had two contacts with Hawaii and I can't even hear a single Hawaii station. I've had three contacts further away from me than Hawaii is. I can definitely get out that far, I guess I'm just not in an area where Hawaii signals bounce down? 

[Northcutt114]

OK...more "science."

I decided to throw some more money at the JCP12 problem. I bought the little aluminum radial plate they sell, a long with a capacitance hat. I thought maybe there was something going on with my eight eyelets on the spike. Maybe they weren't grounding or something. Notes later but the TLDR is that neither item seemed to make a difference.

With all four sections and the coil on, plus the whip; I was able to tune up 60, 40, 20, & 17 meters no problem. I was even able to move the slider around on the coil and adjust the antenna using the SWR analyzer to get it resonant on all those bands. So the G90 could tune it, or I could run it untuned and resonant. Pretty slick.

But when the coil came off, nothing tuned. Couldn't get below 4.0 SWR on any band, no matter the height. The manual says to remove the coil, keep all four sections of pole on and adjust the whip. No dice.

However....I found that if I had someone grip the antenna, I was able to use the SWR meter to find resonance on 10m. And the radio would even tune and TX fine. If someone was holding it. But if they let it go, immediately back to 4.0 SWR and RFI all over the mic. What does that mean?

I then found the pic below on reddit. These instructions are completely different than the ones that come with the antenna. But they were in a thread where people are having the exact same problem I am. Antenna tunes up just fine until the coil comes off. And of course, I find this reddit thread after I have broken down the G90 and put everything away for the night. I guess I'll test it tomorrow.

Thoughts?

 

 

[Northcutt114]

I'm also reading that 10m is near the top end of the JCP12's capabilities. So now I'm beginning to wonder if it has always been like this and I just never noticed. It's easy, if you're new to the G90, to not see the SWR bar at the top. Maybe it was always there and I assumed it was at the bottom because I was a rookie?

 

[WRYS709]

The JPC-12 gets such great reviews on YouTube!

[TNFrank]

1 hour ago, WRYS709 said:

The JPC-12 gets such great reviews on YouTube!

I just didn't like the way the coil was open. The HF-009 has an enclosed coil which will protect it better. For 10M with it you don't need the coil section. 

[SteveShannon]

2 hours ago, Northcutt114 said:

I'm also reading that 10m is near the top end of the JCP12's capabilities. So now I'm beginning to wonder if it has always been like this and I just never noticed. It's easy, if you're new to the G90, to not see the SWR bar at the top. Maybe it was always there and I assumed it was at the bottom because I was a rookie?

 

Use your antenna analyzer function and sweep frequencies above, in, and below the 10 meter band to see where the dip is of the fully extended antenna without the coil.  Then shorten the antenna until the dip is near the top of the 10 meter band. How low does the dip go (SWR).  Is that SWR of 4.0:1 the bottom of the dip? Widen the sweep so you can see the actual dip. If you already did this and I didn’t understand it I apologize.

[WRYS709]

3 hours ago, TNFrank said:

I just didn't like the way the coil was open. The HF-009 has an enclosed coil which will protect it better. For 10M with it you don't need the coil section. 

HF-009: Keep the coil mounted for 10 meters to gain the elevation, just run the coil slider all the way up, to effectively bypass the coil. 

[Northcutt114]

15 hours ago, WRYS709 said:

The JPC-12 gets such great reviews on YouTube!

Yeah, but those guys aren't really testing 10m. If I wasn't trying to get it to tune on 10m, I wouldn't have a negative thing to say about it.

[Northcutt114]

20 hours ago, SteveShannon said:

Use your antenna analyzer function and sweep frequencies above, in, and below the 10 meter band to see where the dip is of the fully extended antenna without the coil.  Then shorten the antenna until the dip is near the top of the 10 meter band. How low does the dip go (SWR).  Is that SWR of 4.0:1 the bottom of the dip? Widen the sweep so you can see the actual dip. If you already did this and I didn’t understand it I apologize.

I did this tonight, both using the manual's instructions for setting up the antenna, as well as using the cheat sheet posted above. Both ways, there was no dip. 4.0:1 across the board, no matter what I did. From 6m all the way to 15. No dip. Flat topped at 4.0.

I'm really baffled. I added the coil and tuned it up to 20m just fine, made a contact with a guy in Oregon. No problem. But for whatever reason, this G90 will NOT tune this antenna on 10m. 

[SteveShannon]

2 hours ago, Northcutt114 said:

I did this tonight, both using the manual's instructions for setting up the antenna, as well as using the cheat sheet posted above. Both ways, there was no dip. 4.0:1 across the board, no matter what I did. From 6m all the way to 15. No dip. Flat topped at 4.0.

I'm really baffled. I added the coil and tuned it up to 20m just fine, made a contact with a guy in Oregon. No problem. But for whatever reason, this G90 will NOT tune this antenna on 10m. 

So if you shorten the antenna completely and leave the coil off where is the highest frequency dip? Sweep every megahertz between 14 MHz and 30 MHz to find all the dips. 

[Northcutt114]

15 hours ago, SteveShannon said:

So if you shorten the antenna completely and leave the coil off where is the highest frequency dip? Sweep every megahertz between 14 MHz and 30 MHz to find all the dips. 

I wish I had seen this before I went out to activate today. I would have tested it.

In other news, amazing activation today. 20m, hunted 16 park to parks in less than 90 minutes. Home before lunch. All QSO's were 55 or higher. So the JCP12 works really well on 20m. 

Now to figure out the 10m problem...

[WRYS709]

This guy goes into depth about the difficulty of tuning the JPC-12 in general and goes band by band 

He does add more radials and points out that if the Radials O-Ring connector is installed upside down, it can possibly knock out the value of the radials

 

 

[Northcutt114]

13 hours ago, WRYS709 said:

This guy goes into depth about the difficulty of tuning the JPC-12 in general and goes band by band 

He does add more radials and points out that if the Radials O-Ring connector is installed upside down, it can possibly knock out the value of the radials

 

 

Yeah, I got motion sick trying to watch that. Good grief. And he's not even doing it correctly, leaving the coil on for 10m.

I bypassed the radial thing by buying the plate adapter. But he's right, if it's not all the way connected and screwed in, you'll have issues.

In other news, activated a new park today on 20m. No problems. 10 Park to Park's all 55 or higher, even busted through a pile up and the guy said I was a "booming 59." Not bad for little 20W in a box.

Maybe I'll only do 10m with the wire antennas.

 

 

[TNFrank]

Rain was a possibility today here in AZ. so I set up the HF-009 to use. Things started out slowly but started heating up after an hour or so and I ended up making 17 POTA QSO's. That little vertical isn't half bad for an antenna you can set up quickly. Even with an SWR of 1.8:1 I was getting out pretty well. All in all it was a pretty good day.