Greyline RF choke with slip-on ferrite beads - common mode line isolator for DX Vertical and DX Flagpole antennas, rated 3-5kW

Greyline RF Choke | Slip-On Beads, 3-5kW Line Isolator

Regular price: $25.00
Sale price: $25.00

The RF Choke is a must-have with any antenna system. It's a must for Greyline Performance antenna systems. Choose from our default sleeve choke, mini 500W choke, and maxi 3500W RF chokers, common mode current line isolators, and 1:1 current baluns.

Ham radio is fun again!

Country/Region of Manufacture: United States

Effective Frequency Range (MHz): 3-300

PEP Power Rating (watts): same as coax cable rating

Choking Impedance Range (ohms): 5 bead: 200-900, 10 bead: 400-1400, 15 bead: 600-1700

Common Mode Attenuation (db): 5 bead: 9-20 db, 10 bead: 16-24 db, 15 bead: 17-25 db

Estimated Insertion Loss (db): .025

Input Connector Type: none

Output Connector Connector Type: none

Ground Connector (Y/N): none

Enclosure Size (LxWxH inches): none

1/2″ / 12.7mm max Cable Size Chokes

Model SLO-1/2 family of chokes are for use with ½” coax cable like RG-8, RG-213, 9913, LMR-400 and similar cables up to ½” diameter – works on all cable impedances (50, 62, 75, 90 ohms, etc). 80-6 meters. Choose SLO-1/2 (5 beads) or for extended choking, choose SLO-1/2E (10 beads) or for super-extended choking choose SLO-1/2SE (15 beads).

Select chokes with a minimum of 500 ohms at your frequency of interest for best results or upgrade to our Mini or Maxi-Choker which chokes up to 10,000 ohms of RF choking.

Select 5 bead version for 80-2 meters use; 10 bead version for 160-6 meter use, 15 bead version for even higher choking power on 160-20 meter frequencies. Power rating is the same as coax cable used power rating.

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Great Improvement!

Living in Florida, prepping for high winds and hurricanes isn't uncommon. Now that I have the tilt-up base installed for my DXF-24 flagpole, that preparation just got so much easier. Remove one bolt, loosen the other, and the antenna comes down easily and goes back up just as easy. It's now a one person job. Besides storm prep, it makes any preventative maintenance less of a chore.

Like the Greyline antenna hardware, the tilt-up base is beautiful. Added bonus; the flagpole just got a little taller! 73, N3EQF

Thomas — you described that base better than our own product page does. 'One person job' is exactly the design goal, and hearing it from Florida during hurricane season means more than any spec we could publish. Thanks. 73, Jon KL2A

Flag pole

I enjoy having my 24 foot flag pole antenna. It looks great and with the pivot bottom it will be easy to repair or maintain if needed. Great job.

Thank you, Don. The 24 is the height where the low bands start paying you back — try 20-30-40 after as darkness approaches. Have fun. 73, Jon KL2A

20' antenna with 9' whip

Fit and finish is top notch. First contacts once installed were Vietnam and Tuvalu (4 bands) from Eastern NC! I ordered the 20' DSV with the 9' whip. No HOA (rather I'm the HOA on my farm:). Talked to Jon K2LA about the truck between the 2" section and the whip and he told me they're developing an aluminum cap for the transition rather than using a truck. I'm looking forward to swapping for that.

I am having difficulty tuning 6m and 160m; all others work fine with my LDG AT1000Pro2 tuner. I also notice the receive is around 2 S units quieter than my OCF Dipole. Still readable but leaves me scratching my head as to why. Perhaps it's me or the conditions in my yard. I am using LMR400 and a Polyphaser. Could be the loss introduced by the added connections.

I ordered the 4 foot extension and the tilt whip. They shipped today. I'm hoping they will make an operational difference aside from the ease of putting it up and taking it down.

Busy company. You need a little patience when communicating with them. Automated answering service picks up when you call. Best to send a clean e-mail from their "contact us" link on the web site.

Edited my review (5 stars) after Jon K2LA's very thorough explanation.

Christopher, Vietnam and Tuvalu on four bands from Eastern North Carolina --
those are serious Pacific paths, and they answer most questions about this
antenna before I type a word. Thank you for the detailed report. Let me take
your three puzzles in order, because the next reader will have them too.

The quiet receive is the one to reframe: quieter is not deafer. Your OCF
dipole is a horizontal wire using its coax as part of the antenna -- which
means it hears your house, your neighbors' switching supplies, and every
bit of common-mode trash along the feedline. The vertical, choked at the
feedpoint, hears less of all that. The honest test is never the S-meter --
it is signal-to-noise. Same station, both antennas: if he is as readable or
better on the Greyline while the meter reads lower, your noise floor
dropped, and that is the feature, not the fault. You already wrote the
evidence yourself: 'still readable.' Watch FT8 SNR numbers side by side
for a week and the meter mystery usually solves itself.

Six and 160 are the two ends of the rope. First check that your tuner
covers 54 MHz at its rated range -- not every desktop auto does, and 6
meters is outside several of them. On 160, a 29-foot radiator is working
hard; dress the ladder line straight and clear -- no coiled slack, off the
ground, off metal -- because coiled balanced line is exactly what pushes a
marginal 160 match out of a tuner's reach. Your 4-foot extension, shipped
today, helps the low end honestly but modestly.

The aluminum transition cap: you are on the list, as promised.

And the fair hit on patience: guilty, with an explanation. Every antenna is
hand-built to order by a small shop, and the same hands that answer the
phone are on the bench. Your instinct is right -- a clean email through the
contact page gets the fastest, most complete answer we can give.

Enjoy the tilt base -- and when the extension goes on, I want the Tuvalu
rematch report. Bands are up and down this month as Cycle 25 slides
down the other side of it's world class peak. The pleasure is ours, Christopher.

Ham Radio is fun again!
73, Jon KL2A -- Greyline Performance
435-200-4902

The only thing you could change is the length of the threaded stud to incorporate flag pole lights. It is not long enough.

Patrick, fair engineering note -- but that stud is prime real estate, and
the penthouse only sleeps one: whip, lights, or gold ball, pick your
tenant. We give the spot to the whip because it is the only one of the
three that pays rent in decibels.

The smart trade is whip up top, lights down low: a pair of solar spots
staked at the base washes the whole flag evenly all night -- which is
exactly what the Flag Code asks for -- and keeps the aluminum overhead
doing its one job, which is Tuvalu after dinner on 20M for you!

Four stars for a part doing double duty as your DX aperture and your
flag truck? We will take that trade too.

Satisfied Customer

Upon receiving the 24’ vertical, I was impressed with the overall quality of the antenna. All parts are made with the finest material and the fit and finish of the antenna is exceptional

I did not get the installation done until the 30th of July and I am having some difficulty tuning until I removed the 1:1 balun I had purchase for it. It appears to load nicely on all bands except 6 meters and 80 meters. This may be an issue with my MFJ 998 tuner. (More to follow on that)

I did notice the latter line to coax black plastic box does not like direct Alabama Sun in late July! It got hot enough to show deformation from the heat!

Update from Charlie WB4MFF: resolved with a tuner reset — now loading the full 160–6! Great work. Ham radio is fun again!

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Greyline RF Choke | Slip-On Beads, 3-5kW Line Isolator

1/2″ / 12.7mm max Cable Size Chokes

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