[Drake] Firing up "4-Line" after 10+ years

[Garey Barrell]

Hi Jim -

You've already had a bunch of good information from the group.

Honestly, you could probably plug them in and turn them on and they would work fine.  However, I 
would NOT recommend that! :-)  The very first thing to do is to check the fuses in each piece.  The 
receiver should have a 0.75A fuse, and the AC-4 should have either a 5A or 6-1/4A.  This simple step 
could save much heartache!

There are at least two ways to go, one is to 'shot-gun' all the electrolytics and go from there. 
There are a LOT of 4 series receivers and transmitters still working just fine with the original 
caps, but they are the exception.  The AC-4R kit from 'theheathkitshop.com' which replaces most all 
of the components in the AC-4 power supply making it good for probably another 30 years or so.  The 
Twist-Lok multi-section cans in the transmitter and receiver are available from 'hayseedhamfest.com' 
and are drop-in replacements.

A second way is if you own or have access to an ESR meter.  If you're not familiar with them, they 
are AC ohmmeters that measure the effectiveness, and to some extent the condition, of electrolytic 
capacitors, in circuit.  If all caps check good, there's a very good chance that both units will run 
for many hours without difficulty, and with the correct fuse in place things should be well protected.

I personally don't like the 'bring it up on a Variac over x number of hours or days!' procedure. 
The usual rationalization for this is to allow the electrolytics to 're-form slowly', but if they 
take that long to reform they're already on life support.  I DO like the light bulb in series with 
the AC supply for first turn-on of an unknown device, as it is positive protection against power 
supply short circuits or bad transformers, and will NOT damage anything if there IS a short.

Essentially you pays your money and takes your chances.  If it's a good pair, and you intend to keep 
them for personal use, I'd go the shot-gun approach.  There is some expense involved, but well spent 
if you can enjoy them without interruption for many years.  On the other hand, if you intend to just 
sell them off you won't get any more for them with the cap upgrades in place so save your money. At 
the very least, replace the BIAS supply caps in the AC-4 before leaving the transmitter on and 
unattended.  A failure of the BIAS supply will key the transmitter, even if it's in standby, and 
destroy at least the PA tubes and whatever else goes before the fuse blows.

Avoid any modifications, especially the garbage 6146 PA sub. It's a kludge at best, and turns a good 
transmitter into a mediocre spur generator.  There are plenty of 6JB6 tubes around, typically for 
less than 6146s.  Also avoid the Sherwood mods unless you need contest grade performance and plan to 
keep them.  They do what they claim, but they are expensive and you won't recover their cost in 
resale.  The bands today are uncrowded enough that unless you are a contester you just won't need them.

Someone suggested that you could probably sell them for enough to purchase a whiz-bang rice box, but 
if you wanted that you wouldn't have kept the C-Line all these years!  :-)   You could always just 
buy an IPhone too.......

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>

Jim Lowman wrote:
> I have a "4-Line" (R-4C, T-4XC, AC-4 and MS-4) that I bought 10 or so
> years ago and haven't used it since.
> Now that I'm retired, I want to get these beauties back on the air.
>
> What is the recommended procedure for firing the receiver and
> transmitter up?
> Should I plan on buying the recap set for the AC-4?
> I have Garey's excellent CDs for this line, as well as for the 2-B receiver.
>
> Thanks for any suggestions.
>
> 73 de Jim - AD6CW
>