开云体育

Hi
My old 1977 FT-301D never had a AM filter. I was wondering where I could find one and how to go about
installing one. The filter board just has the stock CW and SSB filters. I can listen to AM shortwave stations on it but
I think with the filter it would be better sounding?
Fred
N1DEC

Hi Fred.

You are correct that having an AM filter would improve the listening experience. I your case though, given how difficult it is to find a filter and the fact that the 301 isn't general coverage, there are limited opportunities for SWL. Unless you really, really love your 301, it might make more sense to get a portable SWL receiver for around $100. something like a Techsun PL660 or a reconditioned Sony 2001D/2010 (my personal favorites). You'll likely spend more than that on a filter to maybe just listen to 40 meter SW at night?

If you're competent with a soldering iron, performing a capacitor/resistor bypass on the AM slot in the filter board might work, but ONLY if you know what you are doing. I have not personally done this mod myself, so buyer beware..you assume all responsibility for your rig if you attempt this.

There was one listed on the auction site recently. Might check and see if it's still available.

73 -Fred, N8YX

Hi Fred. I've been trying to make this work for a while. I'm no wizard with computers. Calrad was making kits for filters. All my AM filters are in use. Every one I build gets a AM filter, even the one I use on 220. You can change the selector jumper to use an SSB filter but won't sound the best. You can also just change the jumper to the open slot and jump across where the AM filter would go. You can bring the band width down with a cap and a resister. Just takes time to make it bearable. hi Will be REAL wide band but works! Be sure to diddle your AM oscillator on freq as stock they ran 700 hz off for RTTY. If you have a Timewave 599zx sitting around you can bring your skirts in with it in the audio section. The AM filter was also used in the FT-620. That's the only two Yeasu's that I'm aware of that use the 9mhx IF. I have used one out of another radio with some success. Won't fit perfect but will work. Just look for 9mhx AM or 6kc band width filters.
Dave