Saturday, Jan. 30, 2021
Today I had a chance to check out my Knight T-60 paired with my Knight V44 VFO. Each worked separately, but would they work together??
My first mistake was my feedline connection; I failed to connect the correct connector to the SWR meter between the rig and antenna tuner. The T-60 puts out about 40 watts peak on 80 and 40 meters using crystal control.
With my homebrew output cable on the VFO, I connected the two and fired them up. After they warmed up, I had about just slightly less than 40 watts output using the VFO. Success! I tried keying the VFO at first, but no joy running them that way. I had to key the transmitter, and the VFO was running continuously. I assume this reduces the chances of chirp; the transmitted signal was clear and T9DC.
I considered running the pair while using my IC-756PROII for receive, but I don’t have the switching set up for T/R switching. I probably should move my Heathkit HR-1680 and use that with the Knight; I would really like to get my Hallicrafters SX-101A out of the attic, but I don’t really want to fill up my operating desk with that big receiver. I’m really spoiled by the PROIII, hi hi.
As far as T/R switching goes, MFJ makes a RF-sensed T/R switch that is pretty foolproof; its the 21st Century version of the Dow Key relay. One of my YouTube favorite channels host who repairs boat anchors and other classic gear does NOT recommend these new-fangled devices. He recommends using the Dow Key, particularly those with the external contacts. Those external contacts can be used to mute the receiver when the transmitter is active. And as he points out, you can adjust the contacts to engage earlier or later as needed to properly mute your receiver.
In a review of the MFJ units and their ability to protect the receiver from the transmitter, he showed that the lag between shutting off the receiver can still mean your receiver gets a couple hundred milliwatts of RF before the unit switches off the receiver. Something to consider if you want to use one of these units. For what its worth, the lag is only when you depend on the T/R switch’s “automatic” protection switching; the units have a PTT input so you can switch it instantly when the transmitter is keyed. Presumably, the direct keying line provides faster switch-over.
Just checked the HR-1680 manual, and it has a pair of contacts to mute the receiver; the T-60 has a 120vac that is energized across a pair of contacts to turn on a coaxial relay. Now if I can find my 120v Dow Key relay, I might be in business, hi!
ANOTHER HALLICRAFTERS?? Yep! I recenty ran across an eBay listing for a refurbished and fully functioning Hallicrafters HPM-300 MkII. Well, the rig looked good and was priced at a level I could afford, so I snapped it up. Of course, I have a Hallicrafters HPM-300 already, though this one looks nicer. Anyway, my existing 300 is on my main operating desk, so my plain is to replace that one with the new one.
My newly arrived Hallicrafters SR-400 is still in the box awaiting a place to set it up. Not sure just where I’ll set it up, but I may wait until I move my desks from the main shack upstairs. The first desk I plan to move has my original Hallicrafters SR-150 — “Old Ironsides” — installed there, and my preliminary plan is to replace the SR-150 with the Cyclone.
DESK PLANS. My main shack desk is a 4×4 square corner desk, and with three shelves on top of that, I have quite an assembly of gear in one corner. I already plan to remove the Yaesu FT-2000 and matching speaker and replace it with the Yaesu FTDX101MP with speaker/power supply. I also have that HPM-300 on the same shelf; second shelf I have my Heathkit SA-2060 antenna tuner, SWR/wattmeter; FL3 audio filter, and the Heathkit HW-16 and HG-10 VFO.
I’m going to replace the tuner with an MFJ Differential T tuner; and I would like to keep the HW-16 where its at. On the top shelf I have my Ten-Tec Paragon, but that doesn’t have to stay; I also have a lot of ham-related books that I could shelf someplace else to clear up room for something else. I also have a Heathkit HW-8 next to my books.
I hang onto the HW-8 only because I bought it from the builder, the man who was my Elmer. I haven’t used it in years, so it can go in storage.
I have those two 4-foot tables with three shelves on each, so I have plenty of additional room for boat anchors — though none of the shelves are tall enough for the Hallicrafters SX-101A or the National NC-300 receivers.
Enough rambling this installment, its up to the shack!
73 es CUL …. de KY4Z …. SK …. SK …. (dit dit) …