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 Post subject: Re: R388 delimma
PostPosted: Feb Fri 02, 2018 7:22 pm 
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Joined: Feb Mon 25, 2013 8:37 pm
Posts: 538
Location: Seattle, WA
I can’t find the article at the moment, but there’s a minor mod you can make on the 388 that will allow you to feed it to a stereo amp. If I can find the article, I’ll post it. But you might have to google it.

Don


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 Post subject: Re: R388 delimma
PostPosted: Feb Fri 02, 2018 7:42 pm 
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Posts: 5154
Don,

The better audio is derived via the "diode load" output and this is true of numerous Collins receivers.

Note that there are some antenna coil variations between at least some "flavors" of the military oriented R-388 and the civilian market oriented 51J series because the R-388 was originally intended to be usable with a whip antenna. One of the older ER issues had an article on this along with experiments in changing the input winding to match the civilian version. Both versions are very workable but optimal antenna configurations differ.

Rodger WQ9E


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 Post subject: Re: R388 delimma
PostPosted: Feb Fri 02, 2018 7:54 pm 
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Joined: Feb Mon 25, 2013 8:37 pm
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Location: Seattle, WA
Thanks for jogging my memory on the diode load, Rodger. I’m traveling and won’t be able to look for the article for a day or two.

Don


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 Post subject: Re: R388 delimma
PostPosted: Feb Fri 02, 2018 8:07 pm 
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You are welcome Don and I am surprised I remembered it. I was at my daughter's soccer game until 10:30 last night and went to bed after midnight before getting back up at 4:30 so I might be just a little sleep deprived :)

Happy and safe travels!

Rodger WQ9E


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 Post subject: Re: R388 delimma
PostPosted: Feb Sat 03, 2018 6:02 am 
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Joined: Aug Fri 29, 2014 6:17 pm
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Thanks for all the kind words of encouragement guys. Will let you know how goes it.


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 Post subject: Re: R388 delimma
PostPosted: Feb Sun 04, 2018 6:15 am 
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Joined: Aug Fri 29, 2014 6:17 pm
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I dunno. Does $550 for a good clean working R388 with manual, and a good clean working recapped Capehart R390A sound like a deal?





































I spent a few hours messing with both, they work fine. The 390 has rca IF deck but I think the rest is Capehart. Need some tube shields, two for the psu and one that goes over the ballast tube thingy, other than that it seems to be complete. Listened to ambc on both as well as swbc and HAM ssb.

:D


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 Post subject: Re: R388 delimma
PostPosted: Feb Sun 04, 2018 6:25 am 
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Joined: Sep Thu 01, 2016 3:56 am
Posts: 155
Location: San Jose, Ca.
Sounds like a GREAT deal.

Regards, Larry


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 Post subject: Re: R388 delimma
PostPosted: Feb Sun 04, 2018 6:29 am 
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Joined: Feb Mon 25, 2013 8:37 pm
Posts: 538
Location: Seattle, WA
I’ll second that opinion.

Don


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 Post subject: Re: R388 delimma
PostPosted: Feb Sun 04, 2018 6:30 am 
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Joined: Jul Tue 21, 2009 1:38 pm
Posts: 748
Location: SW WA state
Even someone as frugal as me would jump on that deal!
No biggie on the missing IERC tube shields... They are available at modest prices.
Also no biggie on mixed modules on the R-390A: This is the usual case, as modules got mixed around as units were overhauled.


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 Post subject: Re: R388 delimma
PostPosted: Feb Sun 04, 2018 6:24 pm 
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Here's a link to some pics of the faces;
http://s000.tinyupload.com/index.php?fi ... 3709749655


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 Post subject: Re: R388 delimma
PostPosted: Feb Sun 04, 2018 7:14 pm 
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Location: Costa Mesa, California
For me, the problem with a deal like that is both radios are working. I already have too many working radios. I need radios that don't work.

Norm

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 Post subject: Re: R388 delimma
PostPosted: Feb Sun 04, 2018 7:24 pm 
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Norm Johnson wrote:
For me, the problem with a deal like that is both radios are working. I already have too many working radios. I need radios that don't work.

Norm


I know some people that could resolve that problem for you Norm :) They are the type that you can put in a rubber padded room with a cast iron anvil and a foam rubber mallet and somehow they would manage to break both the mallet AND the anvil (and a toe or two).

Rodger WQ9E


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 Post subject: Re: R388 delimma
PostPosted: Feb Sun 04, 2018 8:12 pm 
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Joined: Aug Fri 29, 2014 6:17 pm
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Norm Johnson wrote:
For me, the problem with a deal like that is both radios are working. I already have too many working radios. I need radios that don't work.

Norm



I shall endeavor to keep them working by not messing with them, however the simple alignment procedures will be attempted.

Do you guys run the xtal heaters or not? I've been reading some of the mods and service notes on the 390 and xtals going bad seem to be common, don't want to make things worse if heating them causes them to go out of spec. Plus there's the glorious savings in the power bill due the inoperative xtal ovens.


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 Post subject: Re: R388 delimma
PostPosted: Feb Sun 04, 2018 8:53 pm 
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Joined: Feb Mon 25, 2013 8:37 pm
Posts: 538
Location: Seattle, WA
I can't seem to find the article on a simple diode load mod for the R-388 so you can run the audio out through a stereo amp. I probably found it in the first place by Googling it. On the other hand, there is some great information on the 390 in the "Hollow State Newsletters". You can download the series from the internet.

Don


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 Post subject: Re: R388 delimma
PostPosted: Feb Sun 04, 2018 11:23 pm 
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Joined: Jul Tue 21, 2009 1:38 pm
Posts: 748
Location: SW WA state
Don't run the crystal heater! It's not necessary, and there is a good chance that the thermostat will stick on, causing damage to the unit.
There are plenty of crystals out here, so replacing a bad one isn't an issue, either.
I have run into situations where I did need to replace a crystal or two in a receiver.
Fortunately, I have a good pile of R390/390A parts cars...


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 Post subject: Re: R388 delimma
PostPosted: Feb Mon 05, 2018 12:21 am 
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Location: Costa Mesa, California
Tom, there is a second heater at the 200 KHz / 17MHz oven. Is this a problem to leave on or should it be deactivated? I seem to recall that the oven switch n the back of my radio was off, but when I opened the oven at the RF deck, it was warm.

Norm

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 Post subject: Re: R388 delimma
PostPosted: Feb Mon 05, 2018 5:03 am 
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Don F wrote:
I can't seem to find the article on a simple diode load mod for the R-388 so you can run the audio out through a stereo amp. I probably found it in the first place by Googling it. On the other hand, there is some great information on the 390 in the "Hollow State Newsletters". You can download the series from the internet.

Don



Hi Don, I listened to the 390 in 16khz mode and it sounded fine to me as far as fidelity on ambc, better than the 388 surely, but it will be fun to see what kind of sound comes out of the diode ports on both. Thanks for the tip.


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 Post subject: Re: R388 delimma
PostPosted: Feb Mon 05, 2018 5:10 am 
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Joined: Aug Fri 29, 2014 6:17 pm
Posts: 2390
Norm Johnson wrote:
Tom, there is a second heater at the 200 KHz / 17MHz oven. Is this a problem to leave on or should it be deactivated? I seem to recall that the oven switch n the back of my radio was off, but when I opened the oven at the RF deck, it was warm.

Norm



Also interested in this.

Also also I found this to be of interest to 390 users;
http://www.r-390a.net/Y2K-R3/index.htm
It's where I learned of the xtals and failure issue.


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 Post subject: Re: R388 delimma
PostPosted: Feb Mon 05, 2018 2:56 pm 
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Joined: Jan Wed 20, 2016 7:43 pm
Posts: 112
Location: Yardley, PA 19067
FYI...Chuck Rippel still restores R390As. He takes on about 10 a year and only works on one at a time. Restoration requires about 4 to 6 weeks depending on condition, mods done by previous owners, etc. He will not accept basket cases. Last year Chuck restored a 1958 Motorola 390A and a beautiful 1967 EAC 390A for me. The cost wasn't inexpensive but they worked like Swiss watches after he was done. Given the mechanical and electrical complexities of these receivers were far beyond my skill set I had Chuck do the work. I was able to sell the EAC 390A for $2500 (it looked like it just came off the production line). Add to the mix, Chuck is a really nice guy and goes out of his way to offer assistance and support.

Harry


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 Post subject: Re: R388 delimma
PostPosted: Feb Tue 06, 2018 5:13 am 
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Joined: Aug Fri 29, 2014 6:17 pm
Posts: 2390
Now to find out what tube shields it needs and post a wtb. I appreciate every comment, thanks for the help folks.


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