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Title: Questions abot using an XTAL on my EFJ Valiant Post by: w1jto on July 31, 2020, 05:53:04 PM Got a 3885 xtal today... advertised as tested. Tried it out on my working EFJ Valiant in both positions, C1 and C2 spoiler - Neither worked.
First I fired up 3885 with my VFO and it worked perfectly full 150 carrier, nice modulation. Switched to C1 (pins 3, 5) ... Nothing seen on a remote receiver panadapter... No carrier... Meter on Valiant showed no grid or plate either Switched back to VFO and it was right on the money, again.... SO any chance XTAL is just dead ? Besides setting my valiant to C1 anything else (knob dial, etc) I need to do ? Please don't tell me I need a 455 offset :-) Any ideas on testing the XTAL with a multimeter or another method ? 73 John W1JTO Title: Re: Questions abot using an XTAL on my EFJ Valiant Post by: n1ps on July 31, 2020, 06:57:03 PM Your not alone. I dont understand how any of them work as the wiring for the osc circuit runs all over the place.
Peter Title: Re: Questions abot using an XTAL on my EFJ Valiant Post by: Pete, WA2CWA on July 31, 2020, 06:59:16 PM Got a 3885 xtal today... advertised as tested. Tried it out on my working EFJ Valiant in both positions, C1 and C2 spoiler - Neither worked. First I fired up 3885 with my VFO and it worked perfectly full 150 carrier, nice modulation. Switched to C1 (pins 3, 5) ... Nothing seen on a remote receiver panadapter... No carrier... Meter on Valiant showed no grid or plate either Switched back to VFO and it was right on the money, again.... SO any chance XTAL is just dead ? Besides setting my valiant to C1 anything else (knob dial, etc) I need to do ? Please don't tell me I need a 455 offset :-) Any ideas on testing the XTAL with a multimeter or another method ? 73 John W1JTO How and when was the crystal tested? Have any other crystals you can test with? Really can't test a crystal with a multimeter but you can build a simple crystal oscillator to test the crystal. Sometimes if you have a RF signal generator you can output the generator into a crystal position. I don't remember the Valiant oscillator circuitry. If the VFO works fine, why even bother with a crystal. You gain nothing. Title: Re: Questions abot using an XTAL on my EFJ Valiant Post by: W1ITT on July 31, 2020, 07:41:29 PM John... It might be worth carefully opening that crystal.... I assume it's an FT243 holder..and checking what's inside. In recent years, as the crystal industry dried up, some have taken to gutting FT243 holders and soldering in a small crystal..such as an HC18 package. This will work in some oscillators, especially sold state ones, and even look good on a VNA, but they won't handle the drive current that some of the classic rigs ran. And don't open the thing over a deep pile carpet ! If it looks like there's a proper crystal blank in there, the old timers used to clean stubborn crystal blanks with alcohol or lighter fluid to get them going again.
73 de Norm W1ITT Title: Re: Questions abot using an XTAL on my EFJ Valiant Post by: N8ETQ on July 31, 2020, 07:46:20 PM Got a 3885 xtal today... advertised as tested. Tried it out on my working EFJ Valiant in both positions, C1 and C2 spoiler - Neither worked. First I fired up 3885 with my VFO and it worked perfectly full 150 carrier, nice modulation. Switched to C1 (pins 3, 5) ... Nothing seen on a remote receiver panadapter... No carrier... Meter on Valiant showed no grid or plate either Switched back to VFO and it was right on the money, again.... SO any chance XTAL is just dead ? Besides setting my valiant to C1 anything else (knob dial, etc) I need to do ? *** you may need to fiddle with the OSC Knob.**** Please don't tell me I need a 455 offset :-) Any ideas on testing the XTAL with a multimeter or another method ? ****** use your RX, Should hear a nice carrier*** **** since that thing has prolly NEVER been used with a rock you may need to switch that switch a few hundred times.** GL Please keep us in the loop.. 73 /Dan n8etq CLE |