Hallicrafters HT-40

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Peter Nierengarten:
KD0ILS here... I was given a lot of older equipment from a Silent Key one of which being a Hallicrafters HT-40.  I'm relatively new with HF mostly hang around 2m and 70cm.  I have a copy of the owners manual, but it doesnt seem to help me much.  I have many questions...
  -  The only equipment i have with this is the transmitter and a copy of the manual 
  -  When i tune it up and receive using my Hammarlund HQ-100 it just sounds like the mic is being activated.

  -  Do i need to have a key in the key socket in order to use the mic? 
  -  I made a microphone plug out of a PL-259 connector since it doesnt use a standard mic plug, i just cut down the center lead to an 1/8".  I was told that this unit requires a high impedance mic, i was curious what the ohm requirement is.  I have a 4 pin  "powered mic" that claims uses 5000Ohms would that work?

  -  Should i replace the mic plug with a standard 4 pic socket?

  -  I do not have the matching reciever/VFO so i'm using crystals.

  -  If i'm using crystals and a microphone, do i need to short terminals 3 and 4 on the back of the unit?

  -  I have a vacuum tube tester and they all appear to be operational

  -  I get the same results whether i connect the radio to a 40w light bulb dummy load or a Slinky antenna

thanks for the help.  I was told this is a pretty good radio, and i'd like to see first hand.

Vinnie Sallustio:
High impedance mic is like a Shure 444 or a unamplified D104. What I do is typically replace the mic connector with a 4 pin Cobra? Why do I do that? With all the crap that people bring me to fix, CB's, rigs, receivers, and such, it appears that the 4 pin cobra is the most common setup. That allows me to not rewire a mic every time I get a different rig. Plus newer D104 hand mics are already wired for a 4 pin Cobra.

I would not leave a modified PL259 for a mic connector.

Nelson Derks:
The mic connector is an old school single button PA system type commonly used in the 60's. If you want to keep the HT-40 original instead of defiling it with a Cobra mic connector and hammertone green paint job you can find the connectors at any decent music store or guitar shop.

I took a peek at the book for the HT-40 that's up on BAMA and that was one of the better Novice rigs back when a Novices were restricted to 75 watts DC input to the final. Damn shame it uses a Six Dairy Queen Five PA as TV sweep tubes are becoming both expensive and hard to find. If you stumble across one at a reasonable price consider rat-holing it against future need.

When 10 Meters is open on the weekends there is a fair amount of AM activity between 29 and 29.2 MC's, typically on Sunday afternoons, and that transmitter would be a good fit for the crowd.

Vinnie Sallustio:

original instead of defiling it with a Cobra mic connector and hammertone green paint job


Peter Nierengarten:
I know i have the manual for this radio, but could someone give me a more simplified and better explained version of how to set up and tune the HT-40 to use it as a AM transmitter for use without a key and only being tuned with crystals.  The problem i'm still having is that i'm broadcasting a carrier, but i cannot broadcast my voice.  Also i'm using a yaesu vx-7r and/or a Hammarlund HQ100 as a reciever if that helps any...


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