Unstable, wide, nasty spur

N7CXI
Posts: 83
Joined: Sun Apr 09, 2017 5:20 pm
Location: Spokane Valley, WA

Re: Unstable, wide, nasty spur

Postby N7CXI » Mon Jan 17, 2022 12:39 am

Thanks, Scott.

I have Kapton tape and a hot air station. Now whether that resistor is in a low enough density area of the PCA that I’d feel comfortable messing with it remains to be seen. He has an original 7000 as well, which is as much fun as the older rigs to tear down and re-assemble.

It’s worth looking at the layout, at least - and running some numbers on the harmonics.

73,
Jim N7CXI
N7CXI
Posts: 83
Joined: Sun Apr 09, 2017 5:20 pm
Location: Spokane Valley, WA

Re: Unstable, wide, nasty spur

Postby N7CXI » Mon Jan 17, 2022 3:07 am

OK, let's see if this works:

If I move the LTM4628 switch freq to 580 kHz, it keeps the spur out of the US ham bands until you get to 10M.
If I remember correctly, the spur level by the time you get to 10M is low enough that while you can see it, it doesn't interfere with normal operation into a live antenna. AFAIK the OM doesn't use transverters.

So... 1.4V on the fSet pin should be close to 580 kHz.
R = 1.4V/10uV = 1.4M .

1.4M should be ok, but I still haven't looked at where the resistor is located to know whether my inner chicken will squawk or not.

73,
Jim N7CXI
User avatar
w-u-2-o
Posts: 5539
Joined: Fri Mar 10, 2017 1:47 pm

Re: Unstable, wide, nasty spur

Postby w-u-2-o » Mon Jan 17, 2022 11:37 am

Check your math, Jim. It's 140K not 1.4M
N7CXI
Posts: 83
Joined: Sun Apr 09, 2017 5:20 pm
Location: Spokane Valley, WA

Re: Unstable, wide, nasty spur

Postby N7CXI » Mon Jan 17, 2022 3:15 pm

Yep, it’s 10uA, so 140K. Thanks for the catch.
I even misstated the units. Go me.

I don’t have the 7000DLE (Orion?) drawings or schematics, so I’ll see if Apache Labs will send them. I thought I had them, but that’s the one full-power rig I haven’t owned.
User avatar
w-u-2-o
Posts: 5539
Joined: Fri Mar 10, 2017 1:47 pm

Re: Unstable, wide, nasty spur

Postby w-u-2-o » Mon Jan 17, 2022 5:00 pm

Yes, it's unfortunate that Apache still hasn't let them be posted publicly here on the forum. They have to supply them under the hardware open source derivative works license, but they don't have to make them publicly accessible, apparently.
N7CXI
Posts: 83
Joined: Sun Apr 09, 2017 5:20 pm
Location: Spokane Valley, WA

Re: Unstable, wide, nasty spur

Postby N7CXI » Wed Jan 19, 2022 5:50 pm

Tony (Apache Labs AU) was kind enough to send me schematics, but no component locator diagram/drawing.
I was able to determine that I want R145, but not where it is, I was hoping to able to tell in advance if the component density was low enough where the resistor is on the board to be able to replace it safely. I'd rather not tear the rig down unless I know there's a reason to.

I sent an email back, we'll see what happens. I already had a copy of the Orion MkII schematic, but no drawing or silk screen + solder mask image.

73,
Jim N7CXI
User avatar
w-u-2-o
Posts: 5539
Joined: Fri Mar 10, 2017 1:47 pm

Re: Unstable, wide, nasty spur

Postby w-u-2-o » Wed Jan 19, 2022 6:39 pm

I got this image right off of the Apache website. Easy day, right on the edge of the board.

1059_1069_1050_1035_Orion MKII REV5.2 small2.jpg
1059_1069_1050_1035_Orion MKII REV5.2 small2.jpg (1.05 MiB) Viewed 11879 times
N7CXI
Posts: 83
Joined: Sun Apr 09, 2017 5:20 pm
Location: Spokane Valley, WA

Re: Unstable, wide, nasty spur

Postby N7CXI » Wed Jan 19, 2022 7:29 pm

Hmm. Didn't think of that, obviously. :-)

Thanks, Scott. Looks like a walk in the park!

I'll report back with results when I have them. I need to get a resistor here, (don't have a 140K precision on hand) and coordinate with the OM that owns the rig.

73,
Jim N7CXI
N7CXI
Posts: 83
Joined: Sun Apr 09, 2017 5:20 pm
Location: Spokane Valley, WA

Re: Unstable, wide, nasty spur

Postby N7CXI » Tue Jan 25, 2022 4:28 am

So here we are - it worked.

I replaced R145 on the Orion MkII board with a 140K 0.1% resistor and all is well.
I'm not sure what kind of solder Apache Labs or their CM used on the PCA, but I had to crank the hot air tool up to 400C before it would melt.

Opening that radio was indeed just as much fun as I remembered, too.

73,
Jim N7CXI
Attachments
w7kev_spur_after.jpg
After mod - change R145 to 140K
w7kev_spur_after.jpg (17.11 KiB) Viewed 11794 times
w7kev_spur_before.JPG
Before mod - R145 is 100K - actually 99.36K measured.
w7kev_spur_before.JPG (24.49 KiB) Viewed 11794 times
User avatar
w-u-2-o
Posts: 5539
Joined: Fri Mar 10, 2017 1:47 pm

Re: Unstable, wide, nasty spur

Postby w-u-2-o » Tue Jan 25, 2022 11:49 am

Nice! Moved it right out of the band. How did the other bands fair? Did you have a spur on 160 to deal with as well?
N7CXI
Posts: 83
Joined: Sun Apr 09, 2017 5:20 pm
Location: Spokane Valley, WA

Re: Unstable, wide, nasty spur

Postby N7CXI » Tue Jan 25, 2022 10:04 pm

Nice! Moved it right out of the band. How did the other bands fair? Did you have a spur on 160 to deal with as well?


Everything's fine from 160M up to 10M, where the harmonics finally creep into the band. The amplitude is so low at the 49th harmonic (28.42 mHz) that it really doesn't mean anything with a "real" antenna. Now what I don't know is if someone had a really good 2M transverter if they'd care about it at the 50th (29 mHz) or 51st (29.58 mHz) . This particular OM doesn't use or care about transverters so it's a solid win.

There's enough info in this thread now to duplicate the experiment on other rigs, but I would advise caution... There's always a risk to doing hot air rework, especially when dealing with solder that has a higher-than-normal melting point - assuming all the Orion MkII boards do. The other risk would be disassembly and re-assembly of the "blue" and "black" rigs. The silver-cased rigs have acres of space internally, but the more compact cases are a PITA - IMHO. ;-)

Thanks for all the help!

73,
Jim N7CXI
N7CXI
Posts: 83
Joined: Sun Apr 09, 2017 5:20 pm
Location: Spokane Valley, WA

Re: Unstable, wide, nasty spur

Postby N7CXI » Wed Jan 26, 2022 6:04 pm

... and to answer the specific question you asked:

Yes, there was a harmonic (well above the noise floor at the OM's QTH) that would end up around 1992 kHz after the rig warmed for a while. That's now moved up in proportion with the rest and above the 160M upper band edge.

73,
Jim N7CXI
User avatar
w-u-2-o
Posts: 5539
Joined: Fri Mar 10, 2017 1:47 pm

Re: Unstable, wide, nasty spur

Postby w-u-2-o » Wed Jan 26, 2022 9:36 pm

That's some very good work there, Jim, and it would seem that it should answer Gary's original complaint that started this topic.

@NC3Z get that rework station fired up, Gary! :D
NC3Z
Posts: 464
Joined: Sun Oct 29, 2017 8:57 pm
Location: Merritt, NC

Re: Unstable, wide, nasty spur

Postby NC3Z » Wed Jan 26, 2022 10:11 pm

If I still had my Pace SMD station!
Gary NC3Z
K9RX
Posts: 414
Joined: Fri Apr 14, 2017 3:47 pm

Re: Unstable, wide, nasty spur

Postby K9RX » Thu Jan 27, 2022 2:33 pm

It's simply removing a SM resistor - a good soldering pencil should do the trick. I do this as needed on the product that I sell. First, use some 0.025 solder to flow into the joint - then just hit it back and forth and pop it off. I'll take a look at doing this as I have those nasty spurs as well. I'm surprised however there isn't a way to filter this out - assuming it's conducted and not radiated.

Gary
K9RX
WR4N
Posts: 91
Joined: Thu Jan 21, 2021 3:29 am
Location: Tennessee

Re: Unstable, wide, nasty spur

Postby WR4N » Mon Feb 28, 2022 11:27 pm

28385F6E-244C-40FB-B70E-53FD02E50280.jpeg
28385F6E-244C-40FB-B70E-53FD02E50280.jpeg (728.46 KiB) Viewed 11365 times


I’ve named mine: “Double Humper” and “Drunken Sailor.” The Drunken Sailor moves around, but generally within 2 kHz either side of 3.620 MHz. The Double Humper appears every 65 kHz all across 75 meters. After 3 months, I believe I finally tracked down the source for the DH: I used my ICOM 705 to locate a trickle charger. Home owner’s neighbor gave me owners cell # and I called her. She’s suppose to disconnect when she gets home from work. Fingers crossed! I think that will take care of DH ... but my Drunken Sailor is identical to what is seen in other posted pictures (blue color after rain, bright, multicolor at other times).
RADIO: ANAN 7000 DLE MK2 (Black Version) Thetis 2.8.11.
PC: HP Desktop - Intel Core i7 (10th Gen) - 16GB memory - 512GB SSD - Intel UHD Graphics 630 - WINDOWS 10 (100% Dedicated to ANAN)
PS: ASTRON 35 AMP (100% Dedicated to ANAN)

Best 73s,
WR4N - David
User avatar
w9ac
Posts: 290
Joined: Sun Apr 09, 2017 4:01 pm

Re: Unstable, wide, nasty spur

Postby w9ac » Wed Mar 02, 2022 3:34 pm

Jim,

You've got more guts than me -- or a really narrow nozzle on your SMT rework station! With Orion's tight board density, I suggest others who don't have much rework experience first consider using de-soldering tweezers or a conical-tip soldering pencil. Without ample care, its easily to blow off other parts with a hot air rework station.

I've changed several parts on my Orion board and what works best for me is placement of the board in a Panavise. The work is done under a light/magnifier on an articulated arm. After heating with a conical tip, Lindstrom SMT tweezers extract and replace the component on the board.

For me, the lighted magnifier is even more important since a recent glaucoma event took 30% of my left eye vision and I'll never get it back. Just a public service announcement to others: get your eye pressures checked at annual intervals, especially as you approach age 60. Glaucoma starts on the vision periphery, and you don't know it's stealing your vision until it's too late. It's especially important for folks who otherwise have been blessed with 20/20 vision through their lives and who rarely get a vision test. End of public service announcement...

Paul, W9AC
N7CXI
Posts: 83
Joined: Sun Apr 09, 2017 5:20 pm
Location: Spokane Valley, WA

Re: Unstable, wide, nasty spur

Postby N7CXI » Wed Mar 02, 2022 4:25 pm

Hi Paul,
No, no special narrow nozzle. :-)

My "secret" is to cut a stencil from Kapton tape that exposes the component I want desoldered. The tape keeps the hot air off the surrounding components. It isn't perfect, but it works. You can get the tape on a 2" x 108' roll on Amazon for $10 or so... That's far more tape than you'll ever need, unless you decide to start using it as winding insulation for baluns and other RF transformers. It's ugly as compared to PTFE tubing, but lower cost and works well enough. (1/4" works better for insulating wire than 2", however)

My eyes aren't as good as they used to be, but still "ok". Sorry to hear about the glaucoma! I do have a yearly eye exam and pay a little extra for the retinal scans. I agree completely on the magnifying light. I found a nice one (Aven 26505-LED-XL3) again on Amazon that has both "warm" and "cool" LEDs and separate dimmers for each group. It also has a "no knob" articulated arm, which I like as well.

Having apparently done my product-placement bit for the day,.. ;-)

73,
Jim N7CXI
User avatar
w-u-2-o
Posts: 5539
Joined: Fri Mar 10, 2017 1:47 pm

Re: Unstable, wide, nasty spur

Postby w-u-2-o » Fri Mar 04, 2022 12:38 pm

Kapton tape masking is no secret, of course.

I bought this microscope for doing surface mount rework and it was worth every penny:

https://www.amazon.com/AmScope-SE400-Z-Professional-Microscope-Magnification/dp/B005C75IVM
N7CXI
Posts: 83
Joined: Sun Apr 09, 2017 5:20 pm
Location: Spokane Valley, WA

Re: Unstable, wide, nasty spur

Postby N7CXI » Fri Mar 04, 2022 4:47 pm

… and it appears that we all spend too much money on Amazon.

I have a similar microscope, but have been on the prowl for one that also has a prism and a 4k camera. That I can afford.
User avatar
w9ac
Posts: 290
Joined: Sun Apr 09, 2017 4:01 pm

Re: Unstable, wide, nasty spur

Postby w9ac » Sat Mar 05, 2022 11:10 pm

A Nikon SMZ series binocular microscope was recently given to me that looks much like the scope that Scott referenced. Nice tool but with the matching base, it weighs about 25 lbs.

My wife does head and neck surgery and recently upgraded her surgical loupes. She passed the old pair down to me. Both items help with detailed PCB work but I have to say that the LED-lighted magnifier on an adjustable arm has been a lifesaver since the Glaucoma event. It has four brightness settings and a "C" clamp mount to easily move it around. Amazon link below:

https://tinyurl.com/yxzmtwst

Paul, W9AC
w8du
Posts: 47
Joined: Wed Nov 13, 2019 11:36 pm

Re: Unstable, wide, nasty spur

Postby w8du » Sun Apr 03, 2022 12:18 am

I am thinking maybe I am having the same problem, but the fundamental appears to be in the 40 meter phone band. The noise is definitely coming in through the antenna because when I disconnect the antenna, it disappears completely. It also abruptly starts and stops with no apparent repeating interval. Any ideas on this one anyone?
Tnx es 73 de Arnie W8DU
interference04022022_1404.jpg
interference04022022_1404.jpg (173.28 KiB) Viewed 10835 times
interference04022022_1358.jpg
interference04022022_1358.jpg (177.71 KiB) Viewed 10835 times
interference04022022_1357.jpg
interference04022022_1357.jpg (172.51 KiB) Viewed 10835 times
interference04022022_1356.jpg
interference04022022_1356.jpg (167.22 KiB) Viewed 10835 times
interference04022022_1355.jpg
interference04022022_1355.jpg (166.74 KiB) Viewed 10835 times
interference04022022_1354.jpg
interference04022022_1354.jpg (171.94 KiB) Viewed 10835 times
rdwing
Posts: 92
Joined: Sat May 21, 2022 2:05 am

Re: Unstable, wide, nasty spur

Postby rdwing » Tue Aug 23, 2022 8:02 am

Just wanted to let everyone know that this is still a problem with latest hardware revisions. A new and recently received 7000 DLE Mk3 still contains these spurs, quite bad actually. I quickly measured the following while terminated in a 50ohm load. There are definitely more, but I didn't yet take the time to go through and measure them all yet.

1985 khz -91 dBm
3574 khz -106 dBm
3970 khz -98 dBm
User avatar
w-u-2-o
Posts: 5539
Joined: Fri Mar 10, 2017 1:47 pm

Re: Unstable, wide, nasty spur

Postby w-u-2-o » Tue Aug 23, 2022 11:36 am

It's a safe bet the value of R145 was not changed. Apache appeared to make the smallest number of changes possible associated with parts substitutions for obsolescence only.
User avatar
S_Car_Go
Posts: 5
Joined: Sun Aug 14, 2022 8:13 pm
Location: Houston, Texas

Re: Unstable, wide, nasty spur

Postby S_Car_Go » Tue Aug 23, 2022 1:26 pm

I have the GEN III Orion board in my brand new 7000DLE. I shorted the antenna connection when I went spur hunting. Some spurs are narrow and some are quite wide. I did a quick scan and found the following;


Khz Level
---------------------
1020 -115
1190 -120
1220 -105
1320 -125
1430 -115
1590 -110
1990 -100
2240 -125
2390 -115
2390 -110
2440 -105
2445 -105
2650 -115
2785 -120
3180 -125
3580 -110
3980 -115
4337 -100
5172 -105
5923 -95
7957 -125
8749 -110
12333 -125
12726 -125
13440 -125
Dave - WB5QFZ
rdwing
Posts: 92
Joined: Sat May 21, 2022 2:05 am

Re: Unstable, wide, nasty spur

Postby rdwing » Thu Nov 03, 2022 10:06 am

Thanks for this list. I went through and checked and pretty much have all of these. Actually, have quite a few in the ham bands too.
The 160m one is -86 dBm. Far far louder than even the -100 suggested noise floor from Apache. At the top of 75m, 3977khz is -99. Oof. 5169 khz is -90. Also got one smack in the middle of 40m at 7155 khz, -108 dBm, 20m has one at 14307 @ 110 dbm.

I wonder why some radios have this much louder than others. Your spurs are about 15 dBm quieter than mine. I wonder if anything can be done to quiet these down? I have quite a low noise floor on some bands.
w3ub
Posts: 95
Joined: Fri Dec 14, 2018 6:32 pm
Location: Lunenburg, NS/Florida

Re: Unstable, wide, nasty spur

Postby w3ub » Mon Aug 14, 2023 12:52 pm

What is the physical size of R145 (0805/0402/...)?
Doug

Return to “Everything Else: Antennas, Relays, Switches, Power, Grounding, Cooling, etc.”