4-way wide band antenna coupler for Receive-Only
Don't connect and disconnect cables or flip switches every time you change receivers
Safe DC Static Bleed between your antenna and receivers
A couple of years ago, we were contracted by a TSCM Agency to build some heavy-duty construction Multicouplers ... otherwise called "Antenna Splitters."

These devices function excellently with antenna feeds from 36 Ohms to 600 Ohms, and are flat from well over 100 MHz down to below 100 KHz. There is a very
slight rolloff of about 3 to 6 (additional) dB, down to VLF, at the WWVB 60 KHz Time Signal, and down to 20 KHz, although not guaranteed to meet spec way down
there, since your antenna and receiver impedances will have an affect on that outcome (depending on source/load impedances, as much as - 3 to -6dB additional).
I have used them well into the 146 MHz Ham band with only slight additional loss. These are passive units and do not require power. In practical use, the insertion
loss is about 1.5 dB, or less, from 50KHz - 100 MHz (see specs and qualifications below). This is primarily due to the fact that receivers seldom represent a true 50
Ohm load across their operating bandwidth.
These items are assembled from the best materials required for reliable and long term service.

These are "Receive Only" Multicouplers. The design has been tested for reverse power and have failed at less-than 1 Watt transmitter input (at 50 Ohms). So
maybe they'd be fine with a "Tuna Tin" type QRP rig, but I won't guarantee them for that use, or any transmitting application.

These have great dynamic range; no local flamethrower, powerhouse broadcasters are going to saturate it.

e-mail me to reserve one, or for more info.
Specs (subject to minor variations)
- Insertion loss:   1.5 dB typical* or less within minimum specified load impedance ratings:
                      36 to 500 Ohms source / typical receiver input impedances.
- Bandwidth, 1.5 dB: 0.5 to 100 MHz.
              3-6 dB 20 KHz to 100 MHz (depending on antenna and load impedance match).
- RF Input saturation: Not measured at +80 dB (over S-9) on 50 Ohm line.

(* Theoretical loss with 4 maximum loads of exactly 50 Ohms (resistive) is 12dB, but most
receivers do not represent a true 50 Ohm resistive load. Based on real world sampling with
various source impedances (antenna direct, tuner, preselector) and various, actual receiver
loads, typical loss (signal dBm) is 1.5dB to 3dB.), and rarely up to 1 S-Unit (6dB).

No more cable swapping.
No more switch flipping.
Super bandwidth -- low apparent insertion loss.
M-5030-R, 4-Way Multicoupler Module
$70.00, plus $5.00 shipping (USA only)
- about 1/3 the original sales price.
[As of May 2013 - Only a few left - all new orders must be hand built and will take a few
weeks, depending on demand - e-mail to inquire]

Note: These are just 4-way splitter modules. You must supply the connectors of choice
and the enclosure (metal).

Please click here to contact me for Availability, Payment,
and Shipping.
NEWS!!!   All MC-50030 and MC-1-4 Multicouplers are now
obsolete, and will be upgraded to the
NEW  M-5030-R Model,
which includes the LF band (20 to 300 KHz).   [May, 2013]
Once sold, only the owner of the device is responsible for its safe and proper installation and use. The maker or seller assumes no responsibility for proper and safe installation and
use. Damage, of any kind, including storm static, lightning, and any other hazards of Nature or accident, whether intentional or coincidental, are the sole liability and responsibility of
the owner (customer/buyer).
No refunds, returns, or replacements will be honored unless the item fails to function as specified. Refund or replacement will be determined by the cause of failure. Refunds do not
include shipping charges. The seller is not responsible for lack of technical knowledge in installing or use of the item, damage incurred, or any other personal, material, or monetary
liability. The customer is expected to ask questions of the maker if in doubt as to proper installation and/or safe use, and to read and retain any/all instruction materials.
Returns must be in "as received", re-saleable, factory fresh condition and accompanied by all original paperwork, packing, accessories, etc.
Shipping damage must be claimed by the buyer and filed with the delivery carrier upon receipt of the item. The shipper assumes no liability for shipping damage or any other
damage beyond his control.
A Note on Proper Installation:
These Multicouplers, as with any other equipment, require proper installation for correct functionality. They are usable with antennas with source impedances
from below 30 Ohms to over 600 Ohms. The impedance matching and port isolation is dependent on proper external connections. Each receiver should be
connected to the M-3050-R with a suitable coax cable. All receivers connected to the splitter must have a good ground (common) connection (through the coax)
between each other. Likewise, the antenna circuit must have a suitable signal ground, with a feed impedance of 30 to 600 Ohms. Example: an end-fed antenna
without a ground (signal) return will have a very high characteristic terminal impedance. That kind of condition may reduce the port isolation and possibly
increase insertion loss. Typical suitable antennas are: dipole, end-fed (with ground circuit), active antennas, Windom, extended double Zepp, Marconi, inverted
"L", various verticals (with proper ground plane or counterpoise), loops. etc. Where indicated, a proper
balun or transformer should be considered. Provisions
for proper safety measures for lightning protection and static buildup are the responsibility of the owner/user. Never install antennas above, below, or near
power lines. Always be careful when climbing and installing antennas.
I could use lesser-quality parts and lower the manufacturing costs, but as with everything I have offered so far, I try to design to (or close to) MIL-SPEC assembly and
component standards, for quality of performance and operational durability. This design is exceptional and meets the qualifications that I would want for my personal
use. In fact, a similar unit is in use as an output splitter to the receivers in my
listening post. That same design is used in the RFP-1. The design criteria was simple:
minimal loss, wide bandwidth, and high saturation level. If I cannot get back into the business of building splitters, for practical and economic reasons,
someday I may make this proprietary design available to the public.

I wish to thank all of my previous customers for their nice comments and feedback; it's appreciated.
If you really, really need a multicoupler module, you are invited to e-mail me and I will advise you of inventory status or lead time.