[ARC5] BC-459

[howard holden]

I have an ATA CBY52208 and a BC-458A. I use a 500pF variable ACROSS the output, and I match 50 ohms pretty well, a dipole on 80 and a true EFHW on 40. The variable enables me to match both the ATA (80M) and the BC-458A (40M) quite well, below 1.5 SWR. I get 35-45 watts out of both with 520V on the plates, 200 on the screens, and 150 on the oscillator. The variable coil tap is on the about 2 turns from the left side of the window. 

73, Howie WB2AWQ

________________________________________
From: arc5-bounces at mailman.qth.net on behalf of sbjohnston--- via ARC5
Sent: Thursday, February 27, 2025 11:26 AM
To: arc5 at mailman.qth.net
Subject: Re: [ARC5] BC-459

> command radios were designed to run on short antennasThe ARC-5 transmitter's short antenna design can be handy in certain situations, such the time I was in a temporary location and strung a relatively short wire out the window to a nearby tree.  With a chassis connection to the household ground it worked well.  I'm sure some Novices did the same back in the day.  If I intend to drive a 50 ohm resistive load, I added a series capacitor on the output (transmitting type usually, but I have also used a heavy-duty, high-voltage ceramic disk capacitor).  Then the rig thinks it is still looking into a capacitive load and transfers power efficiently.  I believe the rotary inductor ends up close to the bottom of its travel.On the rig under discussion, since it already had been modified with an SO-239 on the front, I installed the series capacitor inside, behind the front panel, in the line running to the center of the coaxial jack.  I think the value was 50 pF.Steve WD8DAS   sbjohnston at aol.com   http://www.wd8das.net/   http://af4k-crystals.com/   --------------------------------------------------------------------   Radio is your best entertainment value.   --------------------------------------------------------------------   Mein Ohr ganz nah am Weltempfänger...