Hallicrafters HT-40

[KD0ILS]

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.
73's 
-Pete

[N4NYY]

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.

[AC5UP]

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.

[N4NYY]

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

Doh!

[KD0ILS]

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...
73's
Pete

[KD0BKH]

I really don't want to rain on anybody's parade, and I'm certainly not a "band cop", but....

My first ever transmitter was one of these, back in 1967, when I was WN0PKJ.  I made a lot of CW contacts with mine - even used the 60 watt light bulb dummy load.  The owner's manual should have most of the answers that you're seeking.  If you don't understand the manual, I'd suggest that you seek out the help of an Elmer who can help you understand the tuneup procedure.

Also, remember that your voice privileges on HF are restricted to 10 meters, specifically 28.3 - 28.5 mHZ.  AC5UP is right about the AM activity on 10 meters, and I agree that your radio would be a good fit for that crowd, but the AM window is outside your operating privileges.  Most of the activity on the tech segment of 10 meters is USB, and good operating practice would suggest against using AM there.  Also (and, again, this is _not_ intended as flame bait), hams don't "broadcast", we carry out two-way contacts (with a few exceptions, like telemetry and radio control models).

Now, to your questions... 

The key jack is a shorting type jack.  IIRC, you need to have an open key plugged in to do 'phone transmission, and PTT can be performed either by closing the key or by shorting across the 3 and 4 terminals on the accessory strip on the back of the radio (hard to remember back 40 years).  When you rotate the "Function" switch to "AM", the key or the PTT will then key the transmitter.

About the mike -  I agree with 'UP again on the connector - find a single button PA mic connector at your local music store.  You don't need the 4 pin connector, as PTT can be performed with the terminals on the back, which are conveniently located right next to the mike connector.  The mike you have should be fine, although I wouldn't crank up the power on it - just use the mike gain pot on the rear panel to adjust the input level.

Hope you'll consider upgrading to General, so you can avail yourself of the additional operating privileges that will be open to you.  There are AM windows on several different bands, and it's good to see some of these classic rigs brought back into service.

73,

Ed - KD0BKH

[KX5JT]

Phone (including AM) is allowed in the 28.300 to 28.500 portion but only USB by a Technician class operator.

I don't buy this "good operating practice" because AM is a perfectly fine phone mode for all of the bands that allow phone on HF and all the frequencies that allow it.  When you allow someone to paint a mode into a corner, problems arise.  The "AM window" is a myth, there is no such thing.

Nevertheless, the Technician class is only allowed USB on 10 meters so I would suggest studying and upgrading!  Most AM on 10 meters is found between 29.000 and 29.100 Mhz and one must hold at least a General class to operate those frequencies (and AM on 10 meters).

[G3RZP]

If need be, it would be possible to do some rewiring around the 6DQ5 socket and use a 6146 - depending whether or not 6DQ5s can be had for less than both arms and legs.

But perhaps not a job for someone unfamiliar with tube gear.

[KD0BKH]

KX5JT
Phone (including AM) is allowed in the 28.300 to 28.500 portion but only USB by a Technician class operator.

I don't buy this "good operating practice" because AM is a perfectly fine phone mode for all of the bands that allow phone on HF and all the frequencies that allow it.  When you allow someone to paint a mode into a corner, problems arise.  The "AM window" is a myth, there is no such thing.

And I said I'm not a "band cop".  Since the OP has apparently left the building, just a quick statement agreeing with you.  You can feel free to use the 28.3 - 28.5 technician allocation for AM anytime you wish, because you have a legal "right" to do so.  However, there are more than enough band cops around who will be hounding you to stop, something that I thought a relatively new technician class licensee really didn't need to have dropped on his plate.  I'm certainly not "paint(ing) a mode into a corner" - just suggesting operating in a manner consistent with the vast majority of other hams.  I operate regularly in the technician allocation just to give those licensees someone to talk to, on the premise that working "some" HF will maybe get them thinking about upgrading.  What I don't do is intentionally plunk a fat carrier in what is a relatively restricted allocation "just because I can".  I also don't operate LSB on 10 meters, despite the "myth" that we use LSB below 30 meters and USB above, but I'm certainly free to use the other sideband if I choose to.  I, like all the rest of us, can only "work 'em if I hear 'em".

Going along with the, admittedly, "gentlemen's (or women's) agreement" band plans seems to reduce everyone's stress level a bit, and was the only basis for my suggestiion.  BTW, my apologies for my failure to point out to the OP that he's not allowed to use AM on 10 meters in the first place - I was hoping that my suggestion to work with an Elmer would have led him to that realization....

Nevertheless, the Technician class is only allowed USB on 10 meters so I would suggest studying and upgrading!  Most AM on 10 meters is found between 29.000 and 29.100 Mhz and one must hold at least a General class to operate those frequencies (and AM on 10 meters).

Sort of what I said in my last paragraph......

Have fun & 73,

Ed - KD0BKH

[KX5JT]

10 meters affords us plenty of space for AM to operate up there between 29.000 and 29.200 so it's not a big deal for me to hang out there.  Just don't get me started on so called "windows", especially on lower bands.

Bottom line is Pete, you need to upgrade my friend!

[N4NYY]

Phone (including AM) is allowed in the 28.300 to 28.500 portion but only USB by a Technician class operator

The bandplan SSB, but does not state AM in any of the bandplan.I can go right to the horse's mouth and see if infact this would be illegal. I have always understood the above as "accepted practice", but not a rule in concrete.

[KX5JT]

Phone (including AM) is allowed in the 28.300 to 28.500 portion but only USB by a Technician class operator

The bandplan SSB, but does not state AM in any of the bandplan.I can go right to the horse's mouth and see if infact this would be illegal. I have always understood the above as "accepted practice", but not a rule in concrete.

I have no idea what you are talking about.  Whose bandplan?  The ARRL?  The IARU? 

I only go by the FCC for legalities because they are the only ones that matter legally.   The FCC allows all types of AM emmissions, including single sideband supressed carrier or double sideband full carrier or any variation in the 28.300 to 28.500 except for technicians, wherein it allows only upper sideband supressed carrier.

Now, "accepted practice" depends on who is doing the accepting and the practice.

[N2EY]

Phone (including AM) is allowed in the 28.300 to 28.500 portion but only USB by a Technician class operator

The bandplan SSB, but does not state AM in any of the bandplan.I can go right to the horse's mouth and see if infact this would be illegal. I have always understood the above as "accepted practice", but not a rule in concrete.

I have no idea what you are talking about.  Whose bandplan?  The ARRL?  The IARU? 

I only go by the FCC for legalities because they are the only ones that matter legally.   The FCC allows all types of AM emmissions, including single sideband supressed carrier or double sideband full carrier or any variation in the 28.300 to 28.500 except for technicians, wherein it allows only upper sideband supressed carrier.

Now, "accepted practice" depends on who is doing the accepting and the practice.

The point is that KD0ILS is a Technician, and cannot legally operate AM anywhere on 10 meters. The HT-40 cannot do SSB.

---

To me, the word "subband" means "band segments defined by regulation". For example, 7125-7300 is the 40 meter Extra phone/image subband in R2.

OTOH, "bandplan" means "gentleman's agreement" which is not part of the regulations. For example, we use LSB on the bands below 30 meters and USB on the bands above (60 meters isn't a "band", it's a group of channels). We do this for historical and practical reasons rather than regulations.

73 de Jim, N2EY


73 de Jim, N2EY

[N4NYY]

I have no idea what you are talking about. Whose bandplan? The ARRL?

Ths ARRL bandplan. I was not aware that Techs were limited to SSB on their 10M allotment. That is because I passed right to General, and I have never been on AM on the ham bands. I thought the only limitation was USB on 60M.

[AC5UP]

The Tech license has a few more restrictions dealing with frequency and mode than General... Voice privilege is limited from 28.300 to 28.500 @ < 200 Watts USB only, then essentially unrestricted (with some power limitation) above 50.00. A Tech also has CW (only) privileges on the low end of 80, 40 and 15 Meters.

Download this and put a copy on the desktop of your computer: http://www.arrl.org/files/file/Regulatory/Band%20Chart/Hambands-color.pdf

From my perspective that's another reason to upgrade to General.......... Fewer band restrictions to remember.