Garage Door Opener RFI Kit

Bullet 50:200 (4:1) HF Balun, 1.8-61 MHz, 500/1500 Watts PEP, Loop, OCF, ZEPP

SKU Bullet-4B-500EB
$89.95
Bulk pricing available for quantities of 2 units or more
PEP Power Rating
1
Buy more, save more
QuantityPrice per itemDiscount
2 items$79.9511% off
Save this product for later
Customer reviews
No reviews yet. Only signed-in customers who bought this product can leave reviews. To leave a review, sign in
Share this product with your friends
Bullet 50:200 (4:1) HF Balun, 1.8-61 MHz, 500/1500 Watts PEP, Loop, OCF, ZEPP
Product Details
Country/Region of Manufacture: USA
Type: NEW
Input ohms/Output ohms: 50 in, 200 out
Frequency Range < 2:1 SWR (MHz): 1.8-61
PEP Power Rating (watts): 500/1500
Input Connector: UHF SO-239
Output Connector(s): Eyebolt/Wingnut
Transformer Topology: Broadband
Hardware Type: Stainless - 1/4"
Antenna Compatability: OCF, Zepp, Folded Dipole, Loop

The Bullet-4B-500 and SBullet-4B-1500 are multi-core core baluns with a compact enclosure (looks like a bullet) enclosure that is physically lightweight but electrically robust and easy to transport for your portable loop antenna solution or permanent installation. Halyard hoist at top of balun for convenient attachment point. Input is via SO-239 coax connector and output with side eye bolt output. Choose your model rated 500 or 1500 Watts PEP from 1.8-61 MHz.

This transformer requires a feed line choke (see related products) to isolate the coax feed line from the antenna. A coax noise filter at the radio end of the coax is also recommended for best results.

Vertical Delta Loops

Multi-band vertical delta loops can be oriented several way but the most popular is to have the “pointy” end at the top (usually a single support) and the lower horizontal ends just out of reach of humans and animals. Best feed point at the top for multi-band use with a 4;1 balun. CUt total wire length to 1005/F (MHz) where F is lowest band frequency of use..

Single band vertical delta loops are best fed 1/4 wavelength (246/f(MHz)) from the top point down one side. Vertical delta loops use the same 2:1 baluns as the horizontal loops.

NOTE: We rate our Bullet baluns (and ununs) VERY conservatively at 500 watts PEP with a 50% duty cycle. Some manufacturers selling low cost baluns may use a 5% duty cycle for their PEP rating to make it appear you get a higher rated balun for a lower price, but you may in fact be getting be getting less. Their 1500 watts PEP really means 75 watts continuous or 150 watts at a 50% duty cycle compared to our 250 watts at 50% duty cycle. Our baluns typically cover a larger frequency range under 2:1 SWR which make your transceiver happy and probably will last longer with less electrical stress.

Remember we over engineer our products, to out perform our competition - just compare the weight of our baluns to theirs and you will know we put much more into our products so you don't have to worry about failure at a critical moment.


Christmas lights or yard lights with switching DC power supplies are often the RFI source and a clamp on ferrite bead on the AC AND the DC side feeding the lights is needed to help suppress the switching power supply RFI noise.  Suitable snap on beads are FSB31-1/2 for the 1-250 MHz range.

We have also had reported wireless HDTV boxes, and FOSCAM and AMCREST security camera systems causing RFI to garage door remote openers. Use our Garage Door Opener RFI kit to suppress the interference to the opener (VICTIM) – you need one kit for each opener.  Maximize the distance from the camera to the openers may also help.  Additionally shield cable to the garage door sensors may be needed depending on severity of the camera RFI.

Obvious Tech Note: make sure your remote batteries have enough energy to activate the GDO or the signal they transmit may not be large enough to over ride the RFI signal, but a fresh battery may be able to overcome the weak RFI source and allow the GDO to operate correctly.