Remote Rig
RRC 1258 Support in English => General discussion forum => Topic started by: VO1HP on 2015-11-25, 02:09:55
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Still refining the remote site configuration and have discovered that stray RF is killing the RR box or the Ethernet link at the TPLink switch. The Actiontec R3000 router is in another building 150ft away ... so I doubt that local RF would be impacting at that distance from the antennas.
It is only happening on 160-80-40-30. But it wasn't happening at the start of construction of the station elements. I have rearranged wiring and location of the web power bar a couple of times. Have installed StarTech shielded Ethernet cables from the tPlink switch to devices (RR Box; Afedri SDR; Digital Loggers Power Bar; PC)...I thought that they were acting as antennas but that doesn't appear to be the case. Have also wrapped the TPlink SG108D switch in Al foil.
The RR box is powered from its own 12vdc shielded PS (not a wall wart) but the red/black power wire is about 5-6ft long. Plan to move the PS next to the RR Box and shorten the lead to a few inches. Will also remove the PS from the web bar and plug it into a separate wall outlet as I never want to power it down anyway. Will also add some snap on ferrite to the cable from the RR box to the K3. There is No ground on the RR Box. ...should I add one ??
On 160/80/30 can only use 30-35W; On 40 can get to 50w . 80-10 antenna is HF6V with 1.3-1.6 SWR on low band ends. 20-15-10 can run full 100W. 160 inv L with FCP and inline choke.
Anyone else experiencing RF knocking the RR box offline?
Frank VO1HP
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Hi Frank
i had & have same problem. 80-60-40-30m bands. I could not TX more then 50-60w. What i did is adding snap ferrites on all the power lines that are 220v and 13.8V / Lan cables / cat232 cables. Now i can TX 500W on 80-40-30 without any problem.
TX on 60meters still "kills" my router connection but i think it is due to high SWR because i am loading via the KPA500 tuner the the 40meter dipole for 60m.
I will add a new dedicated dipole for this band and hope to solve this issue as well.
Good Luck
Ziv- 4Z4OQ
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Ziv
Thanks for your note. That gives me some hope of clearing the problem. I have ferrite beads on connections to K3 from RR box but need to add mote to the various 110VAC lines and to 13vdc lines too K3 and RR box. My router is separated from the ham gear by 150ft of buried ethernet cable so am wondering now if this cable is picking up inside the building by 30ft and acting as an antenna. above 14 mhz can use full power....just a problem from 10.1 mhz down.
Do you know about the spec on the ferrite bead you used? what type #43 ?
Frank VO1HP
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Hi Frank
Yes 43.. See below
http://www.mouser.com/ProductDetail/Fair-Rite/0431164281/?qs=KmHvPbTOE4S%2fbA3UyJViJQ%3d%3d
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OK Ziv
Thanks....I have quite a collection of snap-ons. Going to the site today to install as many as i can on various wires.
Frank VO1HP
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Hi Frank and Ziv,
Mix 31 seems to be a new favorite. See the article by K9YC. Here's the link and a text snip.
http://audiosystemsgroup.com/RFI-Ham.pdf
New #31 Material is a Problem Solver
The relatively new #31 material made by Fair-Rite Products is extremely useful, especially
if some component of your problem is below 5 MHz. Measured data for the new material is displayed in Figs 18a and 18b. Compare it with Figs 19a and 19b, which are corresponding plots for the older #43 material. By comparison, #31 provides nearly 7 dB greater choking impedance at 2 MHz, and at least 3 dB more on 80 meters. At 10 MHz and above, the two materials are nearly equivalent, with #43 being about 1 dB better. If your goal is suppression or a feedline choke (a so-called current balun), the #31 material is the best all round
performer to cover all HF bands, and is clearly the weapon of choice at 5 MHz and below. Be-tween 5 MHz and 20 MHz, #43 has a slight edge (about 1 dB), and above 20 MHz they're equiva-lent. We'll discuss baluns in detail in Chapter 6. The new #31 material is useful because it exhibits both of the resonances in our equivalent circuit – that is, the dimensional resonance of the core, and the resonance of the choke with the lossy permeability of the core material. Below 10 MHz, these two resonances combine (in much the manner of a stagger-tuned IF) to provide significantly greater suppression bandwidth (roughly one octave, or one additional harmonically related ham band). The result is that a single choke on #31 can be made to provide very good suppression over about 8:1 frequency span, as compared to 4:1 for #43. As we will learn later, #31 also has somewhat better temperature characteristics at HF.
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Ok thanks K2MK.....I have added 20 type 43 beads today and think the station is now operating properly ....keying works at full power all bands. I say "I think" because an hour after getting back home from the remote the SIP link seems to have lost connection!!.......have flashing yellow light on the RRC unit. I can see the RR Remote connected to the remote router. Have to pursue it in the morning.
I am going to buy some #31 beads to fit Rg58 and Rg213 and power leads to get the maximum impact on 80 and 160.
I have read K9YC paper in the past but will go through it again ....its a great resource and I have followed some of the tips in the home QTH station.
Do you know where is the most economical supplier these days for snap on beads?
Frank VO1HP
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With good balanced antennas, RFI is no problem. I would have started to get rid of the RF which comes back to the schack before trying to stop the RF from comming into the RRC and radio. It's much more difficult if the RF is already in the schack.
73 mike
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At my K3 remote I am still dealing with what appears to be RF leakage on 80/40 m which basically kills the Internet link if power is more the about 12w. The k3/mini does not return to Rx for 5-6 secs and the Mini display is full of errors.
I am using a standard 80/40 trap dipole apex at 30ft which is essentially right over the remote equipment rack. It is fed with Belden RG213 type (9214?) cable. When I first installed the remote I was using an OCF dipole on those two bands and had the same issue. I recently installed the standard dipole hoping the issue would go away but it has not ....so the problem is coming from another source. The same coax was used to feed the OCF.
If I switch to the HF6V and transmit on 40m there is no problem. So the problem must be the coax or bad connector feeding the dipole? ..... The only thing I can do is replace the coax feeding the dipole and hope for the best.
While at the remote station I log into my home pc using teamviewer and key the rig using N1MM function keys...thereby simulating my own presence at the home station. The rig does not return to Rx.....there is a delay of up to 5-6 secs . If I transmit using the paddle while at the remote location all works normally on 80/40 ..... But of course I cannot tell if the link has died because it is not in the keying path.
Just posting this to vent !!...hoping for comments.
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This morning I replaced the coax with new LMR400 and UHF connectors. Also replaced the W2AU balun. Still same issue with RF on 80/40 killing link. Where to turn next?
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I have never heard about anyone having problem with RFI at 12W. You do not write which kind of internet connection you have ? It's much more common that you disturb the DSL-modem from the telephone line than the RRC via the Ethernet cable. But again with only 12W I think the problem is somewhere else, a ground wire which is broken or something.
Mike
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with new coax and balun can tx at about 50w on 80 and about 70w on 40.....higher levels and the rig does not return to receive for 5-6 secs.......using all shielded ethernet cables to switch for various devices. and 150ft of buried ethernet back to FOTS internet modem/router....one leg of dipole is parallel with underground ethernet.
Using vertical antenna HF6V which is away from the ethernet ... operation is normal...very weird combo of issues ...ready to throw in towel for the dipole!!
I am going to disconnect/ and redress all all cables in the rack where K3 and RR box installed and start over see if something changes....will check ground connections as well. what about placing ground on the RR box?? can do it using COM2 or 1 side screws
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probably the long Ethernet cable is the problem. Maybe you can hang the dipole in an other direction or use wifi instead of the long Ethernet cable. I doubt that grounding the RRC itself has any influence.
73 de mike
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Mike
Thanks.....yes beginning to feel that the long Ethernet CAT5 is picking up enough to cause problem. Will focus on that area and see what can be done to rearrange.
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This morning, in rain I relocated, one leg of the 80/40 dipole a few feet higher at the end and further to east, away from buried 150ft ethernet which terminates in my garage located remote...... also placed a #31 toroid with w few turns on the inside ethenet wiring at the router end of the ethernet cable in the house . Can now use full 100w on 40 and up to 80w reliabley on 80m CW. Beyond 80w on 80M the problems still arises.
Oddly when I monitor the STATUS line in both the remote RR box and also the Control at my home QTH i see no errors on the RTP and UDP status lines ...always show 60 and 45 respectively...even when the hangup occurs with the rig. So no apparent errors ....why does rig not return to rx right away??
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Perhaps it's best to start at the source of the RF radiation, the feedline. Many 1:1 isolation baluns offer poor common mode impedance to stop feedline radiation.
A simple balun with 5-6 turns of coax through several mix 31 snap-on ferrites at the antenna feedpoint is a good place to start. It shouldn't be too difficult to get 2000-4000 ohms of resistive choking impedance. Some cheap baluns offer only a few hundred ohms and consequently work poorly. Shooting for at least 2500 ohms resistive is a good idea.
Once the feedline is properly decoupled with multi-turn mix 31 common mode chokes, the same method will work well for any other wiring in the system that needs decoupling.
In my own system, every cable is choked for RF. My feedline is choked with around 10,000 ohms resistive at 80M and no RF issues. Unbalanced antennas or balanced antennas that are unbalanced due to installation variables will require much more choking.
More power requires more choking. Common mode current increases to the square of the power increase. Double the power generates four times the common mode current.
As mentioned in other posts there are some excellent articles available. Many hams fumble around dealing with RF issues. Grounding is important from a safety standpoint but is almost irrelevant with respect to RF ingress. Proper decoupling - RF choking - is the correct way to deal with this.
Ian
Vancouver BC