I am all about using vintage equipment but if operating a transmitter in the aircraft band you have to be compliant to part 87 and frequency tolerance standards of 30 parts-per-million (ppm). The prog rock may make that standard where a crystal in a tube circuit may not.

Think that for use in a aircraft you have to be type acceptance and all that WW2 or Korean War stuff is way off the list but for use as a ground station you only have to be compliant with 87, but that’s just my understanding and may be incorrect!

Ray F/KA3EKH

From: [email protected] <[email protected]> On Behalf Of Anthony Clare
Sent: Friday, October 3, 2025 10:42 AM
To: MARK DORNEY <[email protected]>; [email protected]
Subject: Re: [MRCA] CR-1 crystals for an RT53B/TRC-7 RT

I also vote for the prog rock if you can get them right now.

Otherwise, Bomar is still doing custom rocks. They had a minimum purchase of $100 and that was two years ago and for two crystals.

n3kcb

------ Original Message ------
Received: Thu, 02 Oct 2025 07:50:46 PM EDT
From: MARK DORNEY via MRCA <[email protected]>
To: [email protected]
Subject: [MRCA] CR-1 crystals for an RT53B/TRC-7 RT

From: MARK DORNEY <[email protected]>

Date: October 2, 2025 at 5:42:03 PM EDT
To: [email protected]

Subject: CR-1 crystals for an RT53B/TRC-7 RT

Hello Everybody,
     I’m putting together an RT53B/TRC-7 VHF RT. The one frequency of real interest is 130.30 MHz ( the set is to be used when a real WW2 C-47 is dropping supplies/paratroops at events). There hasn’t been a decision on what second frequency is to be installed. The Crystal holders are the CR-1. Looking for the crystal holders and a somebody that cuts custom crystals?  Any help is appreciated

Mark D.
WW2RDO