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Post by raider on Jun 29, 2008 20:55:16 GMT -5
Can someone tell me where the yellow wire hooks to a mark II transmit. I understand that the yellow wire is the exciter for the VFO so that the receiver does not pic it up. I understand that this is for 16 mg unit which will work with a 11 mixing crystal. Am I off here? My second question is concerning the PAL A2 which has a mixing crystal of 6 mghz. Can a person substitue this crystal with an 11 to get it to work with a browning? I would really appreciate some help. I also have a tram D201. Will either work with it? Please help
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Post by 2600 on Jun 29, 2008 21:39:14 GMT -5
In the back of my mind is the echo of Roseanne Roseannadanna, Gilda Radner's SNL character from 30-odd years ago. As she'd say, "You sure do ask a lot of questions!"
Cool! I'll try catching them one at a time.
Depends which radio it was built to match. For some radios, the yellow wire is switched to ground, and that turns on the slider's output signal.
On a Browning, it goes to a resistor on the transmitter's oscillator circuit. That way, either the Spot button or the mike will activate it. Easiest way to tell is to watch what comes out of the slider's coax with a 'scope, and then touch the yellow wire to ground on the slider's rear panel. If this turns on the slider's output, you have the wrong one for a Browning.
If this does NOT activate the slider's output, you probably have the right one. Or yours is broken. Somewhere around here I had a schematic diagram of each setup, the "activate-on-ground' and the "activate-on-hot" arrangement. Oughta find those and get them scanned. The markings on the outside of the cabinet do NOT reveal which way the slider is set up inside.
That's right. Since this transmitter's crystal runs ON your receiver frequency, you want the slider, like the crystal, to turn on ONLY when you key the mike or press the Spot button. I gotta see if I can find the old info on what resistor you put on line with that yellow wire. Pretty sure you DON'T hook it DIRECTLY to the 250- Volt Tx/Spot voltage inside the tansmitter.
Yes, I think you are. The Maco slider does NOT use an internal mixing crystal like the PAL slider. The internal design of these two products are ENTIRELY different. The Maco uses a rubber grommet for the dial's reduction drive. The PAL used a Jackson Brothers (metal) planetary-vernier reduction gear on the tuning knob. Like comparing a pop rivet to a MIG weld.
Sorta..... Subbing the crystal alone won't do the whole job. There are three tuned circuits that have to be changed if you want to modify it for a different output frequency. There is a toroid coil on each of these circuits. The crystal oscillator circuit, the mixer circuit, and the output circuit. Those three coils in your PAL are not wound to work on 16 MHz. They're wound for 11 MHz. Other parts, like resistors and capacitors also get changed to match the band that it's configured to cover. The crystal itself is just the tip of the iceberg, if you want to convert a PAL.
No. The D201 has a slider in it already. Not sure why the radio would need two?
Seriously. Someone (else) really ought to put together a DIY conversion guide for the PAL slider. All the desirable versions dried up years ago. But the other ones, that matched 23-channel radios nobody would ever use are still around. Like cutouts in a record store.
73
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Post by raider on Jun 30, 2008 0:23:27 GMT -5
Man I cannot tell you how appreciative I am of your quick response. I would like to wire that maco up to a mark II. If you could find that schematic and send it to me I would be more that willing to pay you for your time. thank you very much
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Post by grimace on Oct 20, 2018 19:19:43 GMT -5
2600 can you post the schematic diagram if you find them
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