On Sat, Jan 24, 2026 at 2:30 PM <[email protected]> wrote:

Send MRCA mailing list submissions to
[email protected]

To subscribe or unsubscribe via the World Wide Web, visit
http://mailman.qth.net/mailman/listinfo/mrca
or, via email, send a message with subject or body 'help' to
[email protected]

You can reach the person managing the list at
[email protected]

When replying, please edit your Subject line so it is more specific
than "Re: Contents of MRCA digest..."

Today's Topics:

1. Re: R390A dropping resistor value (Ray Fantini)
2. Re: R390A dropping resistor value (Doran Platt)

----------------------------------------------------------------------

Message: 1
Date: Sat, 24 Jan 2026 17:42:18 +0000
From: Ray Fantini <[email protected]>
To: Mike Feher <[email protected]>, 'Bill Mellema' <[email protected]>,
'Jeep Platt' <[email protected]>, 'Military Radio Collectors
Association' <[email protected]>
Subject: Re: [MRCA] R390A dropping resistor value
Message-ID:
<DM8P220MB0472999CB89FC869B7C7E7F2B895A@DM8P220MB0472.NAMP220.PROD.OUTLOOK.COM>

Content-Type: text/plain; charset="windows-1252"

I used to do a lot of replacement of rectifier tubes but not so much anymore. The advantages of SS Diodes are obvious, no heat load and higher B+ but the thing that sticks out most in my mind is that when you turn the radio on with solid state diodes the B+ supply goes to stupid levels until the rest of the tubes light up and that can cause stress on the components in the radio. Also, somehow at first the idea was to replace tubes that may not be easy to obtain but have to say I have enough 5Y3 and 6X4 tubes around here to last a lifetime and then some. With the R-390 think you have a better argument being the two rectifier tubes they are using are not that common, and heat load in the R-390 and A version has always been an issue.
Least thats me, your results may be different.

Ray F/KA3EKH

________________________________
From: [email protected] <[email protected]> on behalf of Mike Feher <[email protected]>
Sent: Friday, January 23, 2026 9:46 PM
To: 'Bill Mellema' <[email protected]>; 'Jeep Platt' <[email protected]>; 'Military Radio Collectors Association' <[email protected]>
Subject: Re: [MRCA] R390A dropping resistor value

CAUTION: This email originated from outside of Salisbury University. Please exercise caution when clicking links or opening attachments from external sources.

On a similar subject, I always change out the 3TF7 and put in a dale chassis mount 50 ohm resistor. Works great. 73 ? Mike

Mike B. Feher, N4FS

89 Arnold Blvd.

Howell NJ 07731

908-902-3831

From: [email protected] <[email protected]> On Behalf Of Bill Mellema via MRCA
Sent: Friday, January 23, 2026 9:11 PM
To: Jeep Platt <[email protected]>; Military Radio Collectors Association <[email protected]>
Subject: Re: [MRCA] R390A dropping resistor value

Great?.thanks Jeep

Bill N3WM

Sent from Yahoo Mail for iPhone<https://overview.mail.yahoo.com/?.src=iOS>

On Friday, January 23, 2026, 7:30 PM, Jeep Platt <[email protected]<mailto:[email protected]>> wrote:

Bill, I have the Navy book that shows solid-state rectifiers. I will look it up in the morning...

Jeep K3HVG

Sent from my Verizon, Samsung Galaxy smartphone
Get Outlook for Android<https://aka.ms/AAb9ysg>

________________________________

From: [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]>> on behalf of Bill Mellema via MRCA <[email protected]<mailto:[email protected]>>
Sent: Thursday, January 22, 2026 8:23:33 PM
To: Military Radio Collectors Association <[email protected]<mailto:[email protected]>>
Subject: [MRCA] R390A dropping resistor value

Guys,

I'm in the process of solid stating the power supply on a R390A. I need the value of the series resistor listed in the field change.

If anyone can help, I would appreciate it.

Best 73's

Bill N3WM

[https://s-install.avcdn.net/ipm/preview/icons/icon-envelope-tick-green-avg-v1.png]<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail>

Virus-free.www.avg.com<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/mrca/attachments/20260124/16050271/attachment-0001.html>

------------------------------

Message: 2
Date: Sat, 24 Jan 2026 14:29:50 -0500 (EST)
From: Doran Platt <[email protected]>
To: "[email protected]" <[email protected]>
Subject: Re: [MRCA] R390A dropping resistor value
Message-ID: <[email protected]>
Content-Type: text/plain; charset="us-ascii"

An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/mrca/attachments/20260124/0bbb24f1/attachment.html>

------------------------------

_______________________________________________
MRCA mailing list
[email protected]
http://mailman.qth.net/mailman/listinfo/mrca

End of MRCA Digest, Vol 261, Issue 41
*************************************