|
Title: Audio Transformer Rating Info Needed Post by: Steve - K4HX on May 19, 2013, 12:51:08 PM Got a couple of questions from a fellow ham in a letter recently.
1. What is the impedance or turns ratio of the BC-610 mod transformer? 2. What are the maximum current ratings (both primary and secondary) of the BC-610 mod transformer? 3. Does anyone have the connection info for a Merit A-3120 driver transformer. He's looking to use these in a homebrew rig using 2A3 drivers, 811A modulators and a 4-250 final. Title: Re: Audio Transformer Rating Info Needed Post by: W8ACR on May 19, 2013, 02:21:09 PM Steve,
The mod transformer is 21000 ohm primary to 8000 ohm secondary, 250 watt rating. Merit 3120 is 500 ohm line to multiple secondary tap, step up, 15 watt rating. The 250TH is run at 250mA for phone operation. Ron Title: Re: Audio Transformer Rating Info Needed Post by: KA2DZT on May 19, 2013, 02:32:11 PM 1.62/1 turns ratio. Have to run the 811s at the same voltage as the final to just make 100%.
Title: Re: Audio Transformer Rating Info Needed Post by: Steve - K4HX on May 19, 2013, 02:58:35 PM TNX gentlemen. What is the plate voltage on the BC-610. I should know this since I've had a few BC-610 plate trannies over the years.
Title: Re: Audio Transformer Rating Info Needed Post by: KA2DZT on May 19, 2013, 03:04:32 PM I have a 610 plate xfmr. Two level plate voltage, primary is tapped, I think 2200DC - 2500DC. after filters. A lot of Stancor plate xfmrs were labeled with the DC output voltage (under load after filters) rather than the AC winding voltage.
Title: Re: Audio Transformer Rating Info Needed Post by: W8ACR on May 19, 2013, 03:38:47 PM According to the manual, The final amp plate voltage is 2500VDC on CW and 2000VDC on phone. (TM11-826, page 65)
Ron Title: Re: Audio Transformer Rating Info Needed Post by: W2PFY on May 19, 2013, 04:40:29 PM I actually measured the voltage on my BC610D under load at 250 ma plate current and 50 ma resting current on the modulators at 2125 VDC with a Fluke meter and a Fluke HV probe. The line voltage was 125 vac. The plate meter is in the anode circuit, not the cathode.
Title: Re: Audio Transformer Rating Info Needed Post by: Steve - K4HX on May 19, 2013, 08:07:04 PM Good stuff. Thanks.
If anyone has the connection info for the Merit tranny, let me know. Title: Re: Audio Transformer Rating Info Needed Post by: W2VW on May 19, 2013, 08:09:19 PM Late BC-610 xfmr was rated @ 4800/5720 VCT IIRC .321A.
In reality a late BC-610 xfmr has enough poop to make the old legal limit out the pipe on AM without breaking a sweat. Title: Re: Audio Transformer Rating Info Needed Post by: Steve - K4HX on May 19, 2013, 08:17:17 PM When you say "late", do you mean the potted tranny instead of the older open frame units?
Title: Re: Audio Transformer Rating Info Needed Post by: W2VW on May 19, 2013, 08:25:49 PM Late as in oil filled cube with two primary taps.
BC-610 F and up IIRC. Title: Re: Audio Transformer Rating Info Needed Post by: Steve - K4HX on May 19, 2013, 09:08:48 PM Got it. TNX.
Title: Re: Audio Transformer Rating Info Needed Post by: ashart on May 21, 2013, 10:09:49 AM Here is Merit A-3120 data.
The data given for turns ratios (pri to 1/2 sec) should allow reasonably easy determination of pinouts, remembering that (Z1/Z2) = (N1/N2)^2. Title: Re: Audio Transformer Rating Info Needed Post by: Steve - K4HX on May 21, 2013, 07:33:16 PM Thanks. I have that catalog. I'm looking for the actual terminal connection info. AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
|