Hi to all:
When switching between RCVR and XMTR, by using the "Transceive" switch on the
T4XC, received signal strength remains constant (the same) on some bands while
others bands produces a drop or gain is signal strength.
I am using the calibrator as the received signal with the AGC set t
Hi Dave,
I am now looking at the service manual of TR7. It lists two versions of
digital board. One uses PROM and one uses without. The Drake part number for
the prom is 3040082 at location U201. If the part number is the same on the
R7 manual, I can safely assume they are the same.
With the vers
PTO grounding under this link.
http://wb4hfn.com/DRAKE/DrakeTechTips.htm
73,
Ron WD8SBB
--- On Thu, 1/14/10, A Parker wrote:
> From: A Parker
> Subject: Re: [Drakelist] R4B/T4XB strange issue
> To: captc...@flash.net, drakelist@zerobeat.net
> Date: Thursday, January 14, 2010, 7:19 PM
> Hi Cur
Hi Curt,
Try grounding the rcvr PTO shaft better (it sounded to me like
you're saying it's the rcvr PTO that's the problem). There's a mod
documented somewhere, probably on Ron's site, that will show putting a small
length of braid from ground to that "clunky" pc that has the spring on it.
I have discovered some unused board assemblies and other assemblies for the
Drake UV-3 transceiver. Is there any interest out there for this
hardware? If so let me know and I can give you a list of what I have, but
I do have 220 VCO assy, 440 VCO assy, 440 PA assy, 220 PA assy, 144 PA assy
Good Evening Gents:
Have a newly reworked R4B/T4XB pair that I've been using for a few days
now. This is the one that I filed stripped the PTO and cleaned up.
Anyway, this just started after about twenty hours of on time.
With VFO selector in Sep, the Rx injection frequency shifts at random
Paul -
OK, progress! :-)
The meter circuit is essentially a voltmeter measuring across the shunt
resistor (R36). The "select at test" resistor (R38) is a series
multiplier to convert the mA meter to a voltmeter. Since your 2.2
resistor is "low", you have to decrease R38 to make the "voltme
Thanks for the info on meter Calibration.
Today I put a 6 ohm (closest to 5 that I had) and using .070a x 6 ohm
= .40v at the TP in the B- line. I then removed R38 and replaced it
with a 0-200 ohm trimpot. I got the meter to read on the hash mark
and then measured the pot (about 27 ohms). I the
Paul -
There were at least four different versions of the AC-3.
The first "rare!" version had a filter choke in the 250V supply. It
didn't last very long before Drake realized that a resistor worked good
enough and dropped the extra cost and weight.
The next version (s/n 2501) has the TP.
Ron -
Nope, the 0.5 V sets 100 mA for the TR-(any). Remember that the AC-3
was designed for the TR-3, before there were any T-4X(any)! The correct
TP setting is 0.35 (.070 * 5) for the T-4X series.
I still like the meter to read as accurately as possible (for a $1
meter!) at least at 0.70
Garey and Ron
Thanks for the additional info on bias setting. I still have the
cover off the T4 and the AC4 so I need to continure with the meter
calibration/bias setting. The T4 seems to be working well except the
output is a bit low. I am seeing 110W out on 80 and 40M at this
point. The mete
Dave -
I just took a quick look at the schematics for both, and it appears that
the boards ARE the same, with the exception that TR-7 version has
additional logic for the "transmit enable" function that comes out on
Pin 11. There are also input signals, HB (?) Pin 52, and TX Pin 16.
However
Garey,
I love the idea of the diode, but I would guess 2 series diodes would be
better. The TRany requires .5 volts at the TP. I seen to remember a couple
times when diodes seemed to have lower than ~.6 volts drop. Maybe they were
schotchy diodes or something. Just remember thinking they wer
13 matches
Mail list logo
