Diyanesh: RG designations are JAN (the AN refers to (US) Army Navy, and they refer back to MIL-HDBK-216 and MIL-C-17). They are analagous to RG-XXX (or EIA's WR-XXX) sizes for waveguides. I'm not sure how numbering works (on Waveguides, it's based on dimensions). I couldn't find RG-174 in my old reference (Reference Data for Radio Engineers), but here is description of RG-178B/U: High Temperature, Single Braid Inner Conductor 7 X 0.004" silvered copper-covered steel Dielectric Material Teflon Nominal Diameter of Dielectric 0.034" Shielding Braid Silvered Copper Protective Covering Fluorinated ethylene propylene Nominal Overall Diameter 0.075" max. Nominal Capacitance 29.0 pF/ft Maximum Operating Voltage 1000 Vrms Z=50 ohms On web I found for one brand: RG-174 is also 50 ohms 0.018" inner conductor (7 X 0.0063") 0.060" dielectric (Teflon) 0.084" shield braid 0.11" overall diameter 30.8 pF/ft Looks like they should be fairly similar, but different dimensions which may be important in terminating them with connectors. Looks like they are both rated to 3 GHz and from what I could see, similar in losses. You'd do best to go to your cable vendors and compare spec's side-by-side, as I'm not sure these numbers are representative of all cable vendors, but I'm sure the dimensions are dictated by the MIL documents. -----Original Message----- From: Diyanesh Babu [mailto:cvdbabu@xxxxxxxx] Sent: Friday, May 30, 2003 6:55 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] RF cable standards Hi experts, Could anyone tell me what are RG178 & RG174 standards in RF cables ? Can we use RG174 RF cable alternate to RG178? Thanks in advance. Regards, Diyanesh Babu C. V. Engineer R&D HCL Peripherals Vadapalani Chennai-26 TamilNadu India ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu