[TowerTalk] Voltage Breakdown For Enameled Wire

Steve, W3AHL w3ahl at att.net
Sun Jan 28 22:39:32 EST 2018

I’ve used Essex Allex (Heavy build).  A general datasheet is at:https://essexwire.com/sites/essexwire.com/files/2017-08/Essex-Wire-Datasheet-Allex-EN.pdf  Dielectric breakdown for 18awg is 4,275 volts minimum at max temp, 10KV typical average, higher voltages at room temperature.  Never could find detailed rating by gauge.

You can buy on ebay:  https://www.ebay.com/itm/Essex-Magnet-Wire-10-AWG-Gauge-0-1054-1-LB-31ft-Enameled-Copper-Coil-Winding/232625128866  Cost is 12.05 per pound (31 ft.)

https://www.ebay.com/itm/Essex-Magnet-Wire-12-AWG-Gauge-0-0808-1-LB-50ft-Enameled-Copper-Coil-Winding-/332523079406  Cost is 15.00 per pound (50 ft.)

Steve, W3AHL

Date: Sun, 28 Jan 2018 18:02:55 -0800
From: Jim Brown <jim at audiosystemsgroup.com>
To: towertalk reflector <towertalk at contesting.com>
Subject: [TowerTalk] Voltage Breakdown For Enameled Wire

I'm once again considering winding high power chokes with enameled wire. 
Zo of a closely #12 pair is about 53 ohms, which makes it desirable IF 
breakdown voltage is sufficient. I would appreciate for sources of #10 
or #12 enameled wire with published breakdown specs.

I've found that THHN (about 93 ohms Zo) works fine for simple antennas 
like dipoles, but some multiband antennas with complex matching/coupling 
systems don't like that much mismatch. We had this problem with the 
Force 12 C3SS, the choke is enameled #12 of unknown pedigree. No 
breakdown issues with a 600W power amp and the antenna is a good match 
to it, but the engineer in me wants to be conservative for legal limit 
to an 80/75 dipole that I use from 3.5-3.9 MHz.

Yes, I know I could put the conductors in Teflon tubing, but that 
increases Zo. I've measured #12 pairs with various Teflon insulation and 
get values around 101 ohms at HF.


73, Jim K9YC

More information about the TowerTalk mailing list