[R-390] EXT: Fwd: 600 ohm audio
Edward Tanton
n4xy at comcast.net
Mon Feb 21 17:31:26 EST 2022
I would like 2 or 3 of the xfmrs but cannot figure out how to privately order them. If they are not gone yet, let me know. I apologize for doing this part openly. Ed Tanton N4XY Sent from my T-Mobile 4G LTE Device
-------- Original message --------From: "Fisch, Michael" <mfisch at kent.edu> Date: 2/21/22 5:18 PM (GMT-05:00) To: Jim Whartenby <old_radio at aol.com>, r-390 at mailman.qth.net Subject: Re: [R-390] EXT: Fwd: 600 ohm audio That is a good price. Several suppliers have the Bogen T725 transformer for when Jim runs out.Mike-----Original Message-----From: r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net> On Behalf Of Jim Whartenby via R-390Sent: Monday, February 21, 2022 4:56 PMTo: r-390 at mailman.qth.netSubject: EXT: [R-390] Fwd: 600 ohm audioDon't know why I have formatting issues with this reflector, geez! 2nd try:If anyone is having trouble finding audio line transformers, I have two dozen NOS boxed transformers available.Rated for both 25 and 70 volt lines at 10 watts, the primary winding has 8 taps and the secondary is set for an 8 ohm speaker.Will transform the following impedances, as printed on the box:62.5 / 125 / 250 / 500 / 1000 / 2000 / 4000 / 5000 /$7.50 each plus shipping from 71901JimLogic: Method used to arrive at the wrong conclusion, with confidence. Murphy-----Original Message-----From: Thomas Chirhart <k4ncgva at gmail.com>To: Tom Frobase <tfrobase at gmail.com>Cc: R390A <r-390 at mailman.qth.net>; Tisha Hayes <tisha.hayes at gmail.com>Sent: Sat, Feb 19, 2022 4:05 pmSubject: Re: [R-390] 600 ohm audioI have a few of these:A-8102’sA-8103’s24572 70.7v voice coils..73 Tom K4NCGSent from my iPhone> On Feb 19, 2022, at 11:17 AM, Tom Frobase <tfrobase at gmail.com> wrote:>> Just as a follow up, I needed a transformer for a unit I recently > sold. I have a box of 25v transformers which were popular before 70v > audio distribution. I found the 1 watt tap was exactly 600 ohms into > an 8 ohm load. They should be very common on EBAY. … Tom, N3LLL>>> On Sat, Feb 19, 2022 at 9:43 AM Tisha Hayes <tisha.hayes at gmail.com> wrote:>>>> (Sigh) late to the conversation but I have a few things to add;>>>> If you are going to browse through ebay for 600 ohm to 8 ohm >> transformers they can be a little pricey; People who have them know >> that they are sort-of-rare and charge accordingly. But... people who >> are selling off the old 70 volt field coil transformers do not know >> the other uses for the transformer as an impedance converter from 600 >> to 8 ohms; You can get those pretty cheaply.>>>> If you look at old speakers there were quite a few that were >> originally designed for 600 ohm sources. Some of the Hallicrafters >> speakers supported a 600 ohm input and if you took the speaker apart >> you would find a little transformer in there.>>>> You can also get transformers that are multi-tap and that allows you >> to match up to 4 ohm speakers as well. Just checking quickly I see >> that radiodaze has the 119DA that would allow you to connect up a 4 >> or 8 ohm speaker just by using a different tap.>>>> Another alternative would be to make your own little audio amplifier >> that can take in a high-impedance input (600 ohms, whatever) and >> drive an output to 4 or 8 ohms. You could even do it with an op-amp >> or a simple transistor based amplifier because those devices don't >> really care about the input impedance that much and are capable of >> driving low impedance outputs (just not at a very high level), so it >> would be good for low impedance headphones or ear-buds.>>>> If you want, you can even find 600 ohm headphones, but nowadays those >> are usually high-end studio headphones. I have the Sennheiser HD600 >> that I do use for radio listening but mostly I use them for high >> fidelity music listening. Those are pricey ($300 headphones) and >> might cost more than your radio. Another place I have found impedance >> adapters are the ones used for David-Clark aviation (pilots) headsets.>>>> Another route I took was to get a Bogen distribution amplifier; This >> is a monsterous, 50 watt audio amplifier that you would use for a >> building and had a 600 ohm input that could drive a variety of output >> impedances. If I ever have a south american dictator surrounded in an >> embassy and I want to drive them crazy/ out of the embassy I would >> use that to play Barney the Purple Dinosaur songs non-stop for a few >> weeks. (or anything from Nickelback).>>>> *Ms. Tisha Hayes*>>>> *AA4HA*>> ______________________________________________________________>> R-390 mailing list>> Home: >> https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmail>> man.qth.net%2Fmailman%2Flistinfo%2Fr-390&data=04%7C01%7Cmfisch%40>> kent.edu%7C0cf4cd927ec34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7d>> d15f26134%7C1%7C0%7C637810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIj>> oiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&a>> mp;sdata=Rwl%2F1eBiOoV3De3jZCaQqUT3M2fc%2FbDUfiT9ZB35xUE%3D&reser>> ved=0>> Help: >> https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmail>> man.qth.net%2Fmmfaq.htm&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd>> 927ec34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0>> %7C637810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJ>> QIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=PgPu%2Fs>> WLx7lugcFoO90N%2BuKoHdzNLxcPPgu2Fa4idJ0%3D&reserved=0>> Post: mailto:R-390 at mailman.qth.net>>>> This list hosted by: >> https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.>> qsl.net%2F&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd927ec34e40557>> c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0%7C6378107773>> 01085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIi>> LCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=aXhsAOLDeEsnntfK%2FAN>> RLucVrR6MuQ%2FF8FE%2FmYqmKis%3D&reserved=0>> Please help support this email list: >> https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.>> qsl.net%2Fdonate.html&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd92>> 7ec34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0%7>> C637810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQI>> joiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=2pj4ptmn19>> BGO3xkh0F%2BYKnAszJJwYHitrkWFPKVGPI%3D&reserved=0>>> ______________________________________________________________> R-390 mailing list> Home: > https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmailm> an.qth.net%2Fmailman%2Flistinfo%2Fr-390&data=04%7C01%7Cmfisch%40ke> nt.edu%7C0cf4cd927ec34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15> f26134%7C1%7C0%7C637810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC> 4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sd> ata=Rwl%2F1eBiOoV3De3jZCaQqUT3M2fc%2FbDUfiT9ZB35xUE%3D&reserved=0> Help: > https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmailm> an.qth.net%2Fmmfaq.htm&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd92> 7ec34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0%7C> 637810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjo> iV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=PgPu%2FsWLx7l> ugcFoO90N%2BuKoHdzNLxcPPgu2Fa4idJ0%3D&reserved=0> Post: mailto:R-390 at mailman.qth.net>> This list hosted by: > https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.q> sl.net%2F&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd927ec34e40557c0> 8d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0%7C6378107773010> 85352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJB> TiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=aXhsAOLDeEsnntfK%2FANRLucV> rR6MuQ%2FF8FE%2FmYqmKis%3D&reserved=0> Please help support this email list: > https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.q> sl.net%2Fdonate.html&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd927e> c34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0%7C63> 7810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV> 2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=2pj4ptmn19BGO3x> kh0F%2BYKnAszJJwYHitrkWFPKVGPI%3D&reserved=0______________________________________________________________R-390 mailing listHome: https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmailman.qth.net%2Fmailman%2Flistinfo%2Fr-390&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd927ec34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0%7C637810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=Rwl%2F1eBiOoV3De3jZCaQqUT3M2fc%2FbDUfiT9ZB35xUE%3D&reserved=0Help: https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmailman.qth.net%2Fmmfaq.htm&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd927ec34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0%7C637810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=PgPu%2FsWLx7lugcFoO90N%2BuKoHdzNLxcPPgu2Fa4idJ0%3D&reserved=0Post: mailto:R-390 at mailman.qth.netThis list hosted by: https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.qsl.net%2F&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd927ec34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0%7C637810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=aXhsAOLDeEsnntfK%2FANRLucVrR6MuQ%2FF8FE%2FmYqmKis%3D&reserved=0Please help support this email list: https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.qsl.net%2Fdonate.html&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd927ec34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0%7C637810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=2pj4ptmn19BGO3xkh0F%2BYKnAszJJwYHitrkWFPKVGPI%3D&reserved=0______________________________________________________________R-390 mailing listHome: https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmailman.qth.net%2Fmailman%2Flistinfo%2Fr-390&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd927ec34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0%7C637810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=Rwl%2F1eBiOoV3De3jZCaQqUT3M2fc%2FbDUfiT9ZB35xUE%3D&reserved=0Help: https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmailman.qth.net%2Fmmfaq.htm&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd927ec34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0%7C637810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=PgPu%2FsWLx7lugcFoO90N%2BuKoHdzNLxcPPgu2Fa4idJ0%3D&reserved=0Post: mailto:R-390 at mailman.qth.netThis list hosted by: https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.qsl.net%2F&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd927ec34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0%7C637810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=aXhsAOLDeEsnntfK%2FANRLucVrR6MuQ%2FF8FE%2FmYqmKis%3D&reserved=0Please help support this email list: https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.qsl.net%2Fdonate.html&data=04%7C01%7Cmfisch%40kent.edu%7C0cf4cd927ec34e40557c08d9f585cd1a%7Ce5a06f4a1ec44d018f73e7dd15f26134%7C1%7C0%7C637810777301085352%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=2pj4ptmn19BGO3xkh0F%2BYKnAszJJwYHitrkWFPKVGPI%3D&reserved=0CAUTION: EXTERNAL SENDER Do not click any links, open any attachments, or REPLY to the message unless you trust the sender and know the content is safe.______________________________________________________________R-390 mailing listHome: http://mailman.qth.net/mailman/listinfo/r-390Help: http://mailman.qth.net/mmfaq.htmPost: mailto:R-390 at mailman.qth.netThis list hosted by: http://www.qsl.netPlease help support this email list: http://www.qsl.net/donate.html
More information about the R-390
mailing list