Being an OT, it is hard to overcome thoughts of past radios that you never owned but wished you owned. I had another one of those consuming and persistent dreams recently that resulted in some new additions to the N6QW shack. Three former US ham radio equipment manufacturers stand out as making gear that fits that paradigm and always caught my eye. Yes, you too -- Collins, Drake and Ten Tec.
My stable includes several pieces of gear from those three. Recently I spotted a Drake T4XC that looked unmolested and fairly good on the cosmetics but had one short coming -- no case top. But I could get it for $120. No stranger to the Drake Twins, I made the move since I had a PayPal balance burning a hole in my pocket.
[If you check my original website www.jessystems.com you will spot a link to the resurrection of a Drake B Line that had been terribly molested and literally rebuilt by me. So, the Drake Twins were not unknown to me.]
My usual procedure is to run a find like this on a Variac to reform any capacitors and just be assured of no internal tube shorts. Then I pulled all of the tubes and cleaned the pins with De-oxit and each tube socket pin was given a toothpick dab of the magic juice.
Next was a full power up and the TR Relay would not kick over. Out with the Sencore Mighty Midget Tube Tester where the 12AX7 in the control relay circuit was found to be marginal. A replacement tube and it went into transmit and full power output. The 12JB6 tubes deliver in excess of 100 watts on 80-20M and about 90 Watts on the 10/15M band.
A listen on an outboard receiver affirmed it worked well on both SSB and CW modes. This now triggered a quest for a matching R4C Receiver. I found one with good cosmetics that with a bit of offers, counteroffers I got for $200. Of the 6 tubes in the radio, I replaced four since I had a stock from prior Drake radio rebuilds. [If its junk I got it.] The radio was now in a working state.
A replacement aluminum insert for the main tuning dial is less than $10 from KE9PQ. He also sells the two critical length cables (Injection and Carrier Oscillator) to make the C Line into a transceiver.
This R4C has a case cover but no optional filters, nor the noise blanker but extra crystals. It turns out that 5 of the 15 extra Crystal positions contained crystals where two positions held crystals for 30M and the 28.0 to 28.5 MHz Segment of 10M. The Stock 10M position starts at 28.5 MHz. These two crystals are worth about $50. The other three crystals cover part of the CB band and SW bands.
One of features of the Drake C Line is they can be used as separates or in a transceiver mode with frequency control from either the Transmitter or from the Receiver. When I cabled things up for transceiver operation, I found that the receiver went almost deaf when the transmitter was controlling things. I reasoned another bad tube in the transmitter, a 6EJ7. A replacement tube and we were back with the same signal levels with either the Receiver or Transmitter PTO. The 6EJ7 is a common tube use in the WRL Duo-Bander so I had a stock of those.
It goes without saying that many of the remedies I used to get the pair working are based on many decades of tribal knowledge. A lot has to do with taking a 10-foot look from above and the potential problem areas and the resolution of same.
Understanding how to read schematics is critical -- always with an eye to what is built and what is in the radio. On the back panel of the R4C is an S Meter Zero Pot. The pot would indeed move the needle but not enough to Zero the meter. Well in looking at the schematic, I found there were actually two pots in the radio which were in series.
One was of course on the back panel, but the other was buried in the radio. (R32 and R33). Light Bulb on the buried pot: it needed to change value and then the back panel pot would zero. YES, that did the trick! Keep in mind part quality 50 years ago and how parts change values over time.
I had a QSO yesterday which was very successful, but not without a huge laugh on my end at some feedback I got. I mentioned that I was testing (for the 1st time) the Drake C Line Twins. The op at the other end was running a Yaesu FTdx101MP (XYZ).
He commented that my microphone (a handheld dynamic mic) sounded good in the mid-range but didn't have a lot of lows or highs. His next comment is that I should go into the menu screen and find the equalizer page and adjust the sliders to add lows and highs. He had no clue the T4XC and R4C were made in the 1970s. I guess if I had an external W2IHY audio box that would be an option but not with just the stock radio.
An N6QW Vintage Operating Position.
A Drake C Line and a KWM-1
W5UX commented in his Drake video (several posts back) that one way to keep the old Drake radios working is to buy a donor unit. So, I hope to find another bargain T4XC and then I will have the cover and spare parts.
TYGNYB.
73's
Pete N6QW
On the failure to follow my own advice -- I bought some boat anchors that potentially would never work. But having rebuilt the B Line I had some confidence that I could fix some of the issues. At this point I have not done a full alignment. But before I start tweaking trimmers and adjusting coil slugs, I want to air test it on all bands. If it ain't broke, don't fix it!