Quality Engineering Solutions Since 1959

Mobile Antenna Springs

For Military, Commercial, and Amateur HF, Robotic & UGV VHF / UHF Masts

General Description

Family of CAL-AV springs. From front to rear: Mark-5, Mark-6, and Mark-7. From left to right in each size: Threaded end, Universal Through-hole (UTH), and Mast Socket. All versions available in mil black oxide. Contact factory for details.
"COMING SOON: All-316-Stainless Marine Spring Line"

CAL-AV LABS produces a family of mobile antenna springs comprising the Mark-5, Mark-6, and Mark-7. These model series represent three basic sizes: 4.65 inches high for the Mark-5, 6.9 inches for the Mark-6, and 8.45 inches high for the Mark-7, each in its threaded-end style. These are commercial grade springs of polished, all-stainless construction, except for the internal tinned-copper braid, which bonds their end pieces for high frequency applications.

Each basic size includes springs of three basic styles:

1. Threaded at each end, e.g. for mounting a whip antenna. Each of these threaded-end springs has an internal tinned copper braid bond between its end pieces. Each size has one standard thread size, plus other sizes available as options. Please see the specifications for each size for details.
   
   
2. A “Universal Through Hole” (UTH), at each end, e.g. for mounting an antenna or mast so that a coaxial cable(s) can be passed through the spring. The UTH end has a central hole surrounded by a pattern of 6 threaded mounting holes. This style allows the spring to be mounted on an enclosure (e.g. for a matching or switching function) and in turn, an enclosure, antenna, or mast can be mounted on the spring. Please see the specifications for each size for details.
   
   
3. A UTH at one end, and a Mast Socket (MSA or MSB) at the other. This allows easy attachment of an antenna, radome, or mast directly to the spring, while allowing passage of the coax(s), control cable(s), etc. The Mark-5 and Mark-6 spring accommodate 1-inch O.D. masts, and the Mark-7 takes a 1.25-inch O.D. Masts are retained with set screws. Please see the specifications for each size for details.

Specifications

STANDARD THREADED END	MARK-5	MARK-6	MARK-7
Size / Height / Nominal Diameter	4.65”/2.1”	6.9”/2.8”	8.45”/3.7”
Weight	2.1 lb	4.875 lb	10.5 lb
Thread (Standard)	3/8-24	1/2-13	5/8-18
Thread (Available – Contact Factory)	Up to 5/8	3/8 to 5/8	1/2 to 3/4
Torque	9 Ft.-lbs.	39 Ft.-lbs.	95 Ft.-lbs
(To achieve 10-degree deflection, length measured from bottom of spring to perpendicular load at 3 ft.)

 

 

 

 




UTH EACH END	MARK-5	MARK-6	MARK-7
Size	4.65” High	6.9” High	8.45” High
Weight:	2.1 lb	4.875 lb	10.5 lb
Center Hole Dia.	0.50”	0.813”	1.00”
Threaded Holes	10-32	1/4-28	5/16-24
Bolt Circle Rad.	0.660”	0.830”	1.100”
Max. Thrd depth	0.370”	0.495”	0.685”

 

 

 

 

 

UTH / MAST SOCKET	MARK-5	MARK-6	MARK-7
Size	4.65” High	8.8” High	12.0” High
Weight	2.4 lb	4.8 lb	12.1 lb
Socket Dia.	1.05 in.	1.05 in.	1.255 in.
Socket Depth	2.50 in.	2.75 in.	3.50 in.
Set Screws	10=32	10-32	1/4-28

 

 

 

 

* MAST sockets for Mark-6 are available for mast diameters of 1.0", 1.25", 1.5" & 1.75". Consult factory for custom sockets

Mark-5 / Mark-6 Size Comparison


(Click photos to enlarge)

		At left is a matte-finish standard Mark-6 HF antenna all-stainless spring assembly.  At right is a Mark-6 based custom mast / radome socket assembly for a military application.  The low-reflectance finish on this all-stainless spring assembly is black oxide per MIL-DTL-13924, CLASS 4.  CAL-AV welcomes inquiries regarding custom spring assemblies.
(STAINLESS & BLACK STAINLESS)

Mark-6 Mobile Antenna Spring Variants

Mark-6 with UTH each end on left; Mark-6 with UTH on bottom, Mast Socket on top to right. 1” diameter mast section with seven RG-303/U cables in sleeve, illustrates through-hole capability.	Mark-6 with mast in socket above, UTH below, mounted on a SINCGARS adapter plate, which is in turn mounted on a vehicular SINCGARS mount.
Underside of vehicular SINCGARS antenna mount and underside of SINCGARS to Universal Through-Hole (UTH) Adaptor Plate, showing safety-wired 1/4-28 bolts.	Close-up of safety-wired 1/4-28 bolts holding Mark-6 UTH base to SINCGARS adapter plate.

Prices: (Single Piece Prices Shown)
Mark-5 Prices:

Mark-5 – Standard, 3/8-24 threaded end	$99
Mark-5 – Threaded end, 3/8 Through 5/8	call w/quant.
Mark-5 UTH5-UTH5, Universal Through-Hole Each End	$145
Mark-5 UTH5-MSA5, Universal Through-Hole Mast Socket	$165
Mark-5 Custom	$ Call

 

 

 

 

Mark-6 Variants Prices

Mark-6 – Standard, 1/2-13 Thread each end, Internal braid	$ 225
Mark-6–1, 3/8-24 Thread each end, Internal braid	$ 235
Mark-6–2, 1/2-13 Thread bottom, 3/8-24 thread top, Internal braid	$ 235
Mark-6–3, 5/8-11 Thread each end, internal braid	$ Call w/qty
Mark-6–UTH6–UTH6, Universal Through-Hole Mounting Each End	$265
Mark-6–UTH6–MSA6, Universal Through-Hole Mounting on bottom, Mast Socket “A” on top.	$285
Mark-6 - UTH6 - MSA6, Universal Through-hole Mounting on bottom, Mast Socket "A"  for 1.00" diameter mast on top	$285
Mark-6 - UTH6 - MSB6, Universal Through-hole Mounting on bottom, Mast Socket "B"  for 1.25" diameter mast on top	$300
Mark-6 - UTH6 - MSA6, Universal Through-hole Mounting on bottom, Mast Socket "C"  for 1.50" diameter mast on top	$310

 

 

 

 

 

 

 

Mark-7 Variants Prices

Mark-7 – Standard, 5/8-18 Thread each end, Internal braid	$ 535
Mark-7 – UTH7 – UTH7 Universal Through-Hole Each End	$ 585
Mark-7 – UTH7 – MSB7 Universal Through-Hole Mast Socket	$ 595
Mark-7 – CUSTOM	Contact Factory

 

 

 

 

Adapter Plates Prices

SINCGARS Mount (6” diameter, nominal, 4 holes, 0.438 dia., 90 degrees apart on 4.5-inch bolt circle), 1/4” Thick 6061-T6 Aluminum, Alodined, ready to prime and paint:
APS-0.375: .250-AL, 3/8” hole at center to mount standard Mark-5	$72
APS-0.5: .250-AL, 1/2” hole at center to mount standard Mark-6	$72
APS5-UTH: .250-AL, to mount Mark-5 UTH5 pattern spring end NOTE: UTH5 is a 0.500 through-hole, surrounded by a pattern of 6 clearance holes for 10-32 screw, every 60 degrees on a 0.660 bolt-circle radius.	$84
APS6-UTH: .250-AL, to mount Mark-6 UTH6 pattern spring end NOTE: UTH6 is a 0.750 through-hole, surrounded by a pattern of 6 clearance holes for 0.25” bolt, every 60 degrees on a 0.830 bolt-circle radius.	$84
APS-BLANK: .250-AL, BLANK, with 0.125 pilot hole at center	$72

 

 

 

 

 

 

 

Also available: Pairing plates; allows pairing two springs side-by-side to double spring constant fore-and-aft, while virtually eliminating side motion. Stainless steel. Intended for mounting on a trailer hitch. Contact factory for details.


Information Sheets

• Mark-5 Mobile Antenna Spring
• Mark-6 Mobile Antenna Spring
• Mark-7 Mobile Antenna Spring

Top of Page



CAL-AV LABS, INC.
2440 N. Coyote Dr, STE 116
Tucson, AZ 85745 USA

info@cal-av.com

---

Antennas | Baluns | Mobile Antenna Springs
Explosive Test Site Range Instrumentation | Illuminated Warning Signs | Special Projects
Home Page | About CAL-AV | How to Order

---

Copyright © 1997-2009 CAL-AV Labs, Inc. All rights reserved.