How Collectable is Halicrafters HA-18?

[WA8MKY]

Fellows: Typical find. Old HA-18 in back of fellow Ham's closet. Hasn't seen daylight in many, many years. Estate attempting to determine worth. Can any Halicrafter fellows give me an idea if this item has much interest within the Halicrafter community? Thank you.

[K7MH]

The HA-18 is a code practice oscillator.
Do you maybe mean the HT-18 transmitter?

[K9STH]

It probably is an HT-18. The HT-18 was sold as a VFO/exciter. It has a power output from around 4 watts on the 80-meter through 15-meter bands down to around 2.5 watts output on the 10-meter band. It could be used to directly drive a grid-driven r.f. amplifier. When used as a VFO sometimes the output power had to be reduced.

The "phone" operation using the HT-18 is actually NBFM ("narrow band frequency modulation") which had some popularity from just after World War II until the mid 1950s. This modulation is made using a reactance modulator which uses a 6BA6 microphone/audio amplifier tube into a second 6BA6 which is the actual modulator. A deviation level control is on the front panel of the unit.

The HT-18 exciters are definitely not "rare". I have seen them "go" for as low as $25 for one in "average" condition to between $75 and $100 for one in excellent condition. I had one a number of years ago that I traded off for something (I can't remember just what).

Here is the RigPix information:

http://rigpix.com/hallicrafter/ht18.htm

Although a lot of the information on the Internet (actually all the same page just different URLs) state that the HT-18 has CW,AM, and FM, that is NOT correct. The HT-18 has only CW and FM operation. To get AM the HT-18 has to be used as a VFO/exciter for a transmitter/r.f. amplifier which, in turn, is AM modulated.

Glen, K9STH

[WD0GOF]

Fellows: Typical find. Old HA-18 in back of fellow Ham's closet. Hasn't seen daylight in many, many years. Estate attempting to determine worth. Can any Halicrafter fellows give me an idea if this item has much interest within the Halicrafter community? Thank you.

The HA-18 by its self is not in too collectable. As a code practice oscillator it is not in too much demand by the general collector. However if you have the original box with the original key and styrofoam insert it does have a little more value to the avid collector who is missing that item.

73, Walt

[W3JN]

The HT-18 is the matching VFO for the HT-20 AM/CW xmitter.

[WA8MKY]

Thanks for the replies fellows. As it turns out it is indeed a HT-18 transmitter.
I'll pass the info on to the estate. Larry

[K9STH]

JN:

Actually, the HT-18 came out 6 years before the HT-20. The HT-18 came out in 1947 and the HT-20 did not come out until 1953. You have to attenuate the output of the HT-18 considerably to use it as the VFO for an HT-20. The Heath VF-1 VFO has plenty of drive for the HT-20. In fact, a VF-1 is the VFO that I use with my HT-20 (see 4th photo at http://k9sth.com/uploads/K9STH_Shack_Photos.pdf ).

I do agree that the HT-18 "looks" very good sitting next to an HT-20. Hallicrafters did not make a true external VFO until around 1962 when the HA-5 was introduced to use with the HT-40 transmitter. Starting in 1954, with the HT-30 SSB exciter (which covered 80, 40, 20, and 10 meters - no 15 meters), Hallicrafters started incorporating VFOs into the basic unit. The HT-40 (1961) was the exception because it was intended to be used by Novice Class operators who were, at the time, restricted to crystal control.

Glen, K9STH

[KM1H]

I have an absolutely mint HT-18 that I use with the same year HT-9. Ive also used it barefoot as a QRP rig, With the SX-42 receiver and R-42 speaker it is a complete operating station for CW, AM and NBFM.

Ive also used the HT-18 padded down to drive a Viking II CDC on 10M AM/NBFM several times.

Carl
KM1H

[W3JN]

JN:

Actually, the HT-18 came out 6 years before the HT-20. The HT-18 came out in 1947 and the HT-20 did not come out until 1953. You have to attenuate the output of the HT-18 considerably to use it as the VFO for an HT-20. The Heath VF-1 VFO has plenty of drive for the HT-20. In fact, a VF-1 is the VFO that I use with my HT-20 (see 4th photo at http://k9sth.com/uploads/K9STH_Shack_Photos.pdf ).

I do agree that the HT-18 "looks" very good sitting next to an HT-20. Hallicrafters did not make a true external VFO until around 1962 when the HA-5 was introduced to use with the HT-40 transmitter. Starting in 1954, with the HT-30 SSB exciter (which covered 80, 40, 20, and 10 meters - no 15 meters), Hallicrafters started incorporating VFOs into the basic unit. The HT-40 (1961) was the exception because it was intended to be used by Novice Class operators who were, at the time, restricted to crystal control.

Glen, K9STH

Glen, the HT-18 came out in '47 and souces cite the HT-20 as coming out in 1950. Hallicrafters apparently provided the HT-18 along with a pair of HT-20s for the Clipperton DXPedition, so apparently they thought it was compatible...

Anyway the HT-20 needs 10V across 300 ohms at its VFO input, according to the manual, so the 2 watts output of the HT-18 should work fine (10V into 50 ohms = 2W).

[K9STH]

JN:

My references show the HT-20 as being introduced in late 1952 for the 1953 "model year". The HT-19 was introduced in 1950. I did look through the various HT-20 manual information for any dates. Unfortunately, there are no dates that I can locate in the manual. However, RigPix at

http://rigpix.com/hallicrafter/ht20.htm

shows the HT-20 as being introduced in 1952 which confirms the information that I have from Brand's book.

According to the HT-20 manual the VFO requirements are 10 volts and the input impedance of the VFO circuit is 300 ohms. This impedance is fixed by a 300 ohm resistor directly to ground from the "hot" side of the VFO input. At 4 watts output the voltage across 300 ohms is 34.64 volts which is definitely too much for the HT-20. Even at 2 watts this is going to be 17.32 volts which will still be considerably more than what is required. Remember, the output of the HT-18 is 4 watts from 80-meters through 15-meters and only on the 10-meter band does it drop to 2.5 watts.

The HT-20 is designed to use a fundamental VFO frequency from the 160 meter band for 160-meters, 80-meters, and 40-meters. It can also use an 80-meter fundamental for 80-meters and 40-meters. For operation on the 40-meter, 20-meter, 15-meter, and 10-meter bands it uses a 40-meter fundamental frequency. As such, we are dealing with a 4 watt output from the HT-18.

10 volts across 300 ohms produces a current of 0.033333 amps. Then, using (I^2)R this results in a power of 0.3333 watts. As such, I would definitely use an attenuator between the HT-18 and the HT-20.

The Viking II, which Carl uses the HT-18 as a VFO, requires the same 10 volts as does the HT-20. It was designed to use the Johnson 122 VFO which, like the Heath copy VF-1, puts out 10 volts. The output from the HT-18 has to be reduced to work with the Viking II.

One thing about the HT-20 is that the frequency coverage is from 1.7 MHz to 30 MHz. Therefore, the transmitter can be used on the WARC bands (30-meters, 17-meters, and 12-meters) as well as the other bands from 160-meters through 10-meters. It also covers the 60-meter band. Unfortunately, since only USB operation is allowed on this band the transmitter cannot be legally used.


1H:

Carl, I am wondering how you use your HT-18 "barefoot" for AM operation? The only modulator in the unit is a reactance modulator which produces FM.


Anyway, the HT-18 is a desirable unit to have.

Glen, K9STH

[WD0GOF]

JN:

My references show the HT-20 as being introduced in late 1952 for the 1953 "model year". The HT-19 was introduced in 1950. I did look through the various HT-20 manual information for any dates. Unfortunately, there are no dates that I can locate in the manual. However, RigPix at


Glen, K9STH

Chuck Dachis' book Radios by Hallicrafters lists the following:

HT-18 1947-49

HT-19 1948

HT-20 1950-53

Note on the HT-18 from the book "There were two production runs of the HT-18. The first run had a 'quilted' bright aluminum dial escutcheon, and the B+ was always on the plate of the 6L6 even in the 'check' mode. The second run had a smoth aluminum dial escuitcheon painted silver gray, and the B+ was removed from the 6L6 during 'check' ".

73, Walt

[K9STH]

The Dachis' book is probably the best reference available on the Hallicrafters equipment. However, just like Penson's Heathkit books (original and revised editions) there are errors. In this case Dachis is just plain wrong!

The very first Hallicrafters advertisements were in the January 1953 issues of the various amateur radio magazines. I have attached scans of the cover of the January 1953 issue of CQ and the Hallicrafters ad for the HT-20 which was on the back of the front cover. If you read the "ad copy" you will see that Hallicrafters is "touting" the HT-20 as the "newest Hallicrafters". Therefore, it definitely was not produced in 1950 or 1951. In fact, the earliest advertisements from various suppliers that I can find is the Allied Radio advertisement which is also in the January 1953 issue of CQ. Attached is also a scan of this advertisement.

Glen, K9STH

[K9STH]

I forgot to mention that both the HT-18 and HT-19 are prominently featured in the Hallicrafters' advertisements in the 1950 edition of the ARRL's Amateur Radio Operator's Handbook. Unfortunately, I do not have the 1951, 1952, 1953, and 1954 editions and therefore I cannot look at the advertisements in those editions.

During 1950 the Hallicrafters' advertisements in CQ Magazine feature the "new and improved" HT-4 transmitter. However, there is no mention of this transmitter in the 1950 Handbook.

Glen, K9STH

[WD0GOF]

The Dachis' book is probably the best reference available on the Hallicrafters equipment. However, just like Penson's Heathkit books (original and revised editions) there are errors. In this case Dachis is just plain wrong!

The very first Hallicrafters advertisements were in the January 1953 issues of the various amateur radio magazines. I have attached scans of the cover of the January 1953 issue of CQ and the Hallicrafters ad for the HT-20 which was on the back of the front cover. If you read the "ad copy" you will see that Hallicrafters is "touting" the HT-20 as the "newest Hallicrafters". Therefore, it definitely was not produced in 1950 or 1951. In fact, the earliest advertisements from various suppliers that I can find is the Allied Radio advertisement which is also in the January 1953 issue of CQ. Attached is also a scan of this advertisement.

Glen, K9STH

The "new HT-20" was the 3rd production run. The first two production runs did not have TVI suppression.

[K9STH]

Then, if this is the 3rd production run, it is completely different as is indicated in the 1953 advertisement (completely new circuitry, 2-piece chassis, and air cooling of the final amplifier tube), I wonder why the nomenclature was not changed! Also, that brings into question the serial numbers. My particular HT-20 is s/n 11 and it is definitely one of the "TVI Proofed" versions. Most of the tubes in the transmitter are original and have late 1952 code dates, at least as I remember (I am not going to remove all of the shields which are secured with about 144 sheet metal screws to verify this).

Hallicrafters was not known to use the same nomenclature on equipment and then reuse serial numbers. The HT-20, along with the SX-88, is one of the more scarce Hallicrafters post war products.

There is absolutely nothing on the serial tag to indicate anything other than a first production run. I have attached a photo of the serial tag on my HT-20. Since the transmitter is pretty heavy, and since it sits on the bottom shelf at my main operating position, I had to "squat down" and take the photo from behind the table. Therefore, the image is not quite "square"!

Glen, K9STH

[K9STH]

I just did a "google" on the HT-20 and other sites confirm the 1952 start date of the HT-20 (actually very late in the year). These include

http://www.radioing.com/museum/tx2.html

http://rigreference.com/rig/2745-Hallicrafters_HT_20 (the photo is not of the HT-20 but the information is)

http://www.radiopics.com/Hallicrafters/Hallicrafters_HT-20.htm


This particular link mentions the 1954 Clipperton expedition that used the HT-20 and SX-88

http://www.mindspring.com/~cacutts/radio/ba/ba5.html

I did come across one site that listed the dates from Dachis' book for all of the Hallicrafters transmitters. However, I didn't get the link copied correctly.

Glen, K9STH

[KM1H]

Carl, I am wondering how you use your HT-18 "barefoot" for AM operation? The only modulator in the unit is a reactance modulator which produces FM.

I never said I used the HT-18 barefoot on AM or NBFM for that matter, just CW. It should be fairly easy to convert to a screen modulator of the 6L6 which should be able to tickle an AB style linear to a respectable level.

As far as the Fairy Tales book Ive found many errors, guesses, etc. It does have pretty pictures.

Carl

[K9STH]

Carl:

It was your statement "Ive also used it barefoot as a QRP rig, With the SX-42 receiver and R-42 speaker it is a complete operating station for CW, AM and NBFM." that was confusing.

As for AM modulating the HT-18: Either screen modulation or cathode modulation could probably be added pretty easily. Of course, even plate modulation could be added without much effort and the modulator wouldn't have to be that large.

As for the Dachis' book, I don't own one. However, I have been informed by several people who do own the book that there are definitely errors in it. Just like Penson's Heathkit book, in which the first edition has quite a few errors that most of them were corrected in the second edition. The second edition of Penson's book now suffers from certain omissions, not incorrect information.

For example, the Heath VF-1 actually came in 2 different versions of the stateside model plus the version that was sold in Europe. In the U.S. versions the units are identical electrically but there was a considerable difference in the front panels. I just happen to have one each of both versions. Also, the Heath AK-5 speaker (for the RX-1 Mohawk) came in 2 versions. The pretty rare first version had a groove cut 3/4ths of an inch behind the front edge whereas the more common version had "plain" sides and top. The first version had about 100 examples made and then Heath "discovered" that they could save a few cents by not having the groove cut into the speaker housing. Again, I have owned both versions and still have the "groove" speaker.

Glen, K9STH

[KM1H]

What I said before you edited it was:
I have an absolutely mint HT-18 that I use with the same year HT-9. Ive also used it barefoot as a QRP rig, With the SX-42 receiver and R-42 speaker it is a complete operating station for CW, AM and NBFM.

There should have been a period after rig....just a typo.

Sorry if it confuses you:rolleyes:

Carl

[K9STH]

Still somewhat confusing! If you put the "barefoot rig" first, or after the statement about the receiver, it would have been much clearer. Anyway, the main thing is that you use the HT-18 either as a CW/NBFM rig "barefoot" and that you use it as a VFO for your HT-9 which then (the HT-9) can run CW, NBFM, or AM.

Glen, K9STH

[KM1H]

Confusing you is one of the joys in life Glen:D

It amazes me how a simple statement to convey that the HT-18 and HT-9 were designed to work together and that the SX-42 and R-42 complete the package of equipment that were all sold at the same time can cause such rambling responses.

I only use the HT-18 on CW when barefoot. And to confuse you even more I dont use the SX-42 on 10M on any mode as I prefer the HRO-60 up there where it is used on AM and NBFM. And since the HRO-60 is paired with the Viking II I have to replace the 122 VFO with the attenuated HT-18 if I want to work NBFM.

Is that as clear as mud by now Glen...:eek: I got a headache just reading it;)

Carl

[K9STH]

Nope! Not confused at all now!

For NBFM I usually use my Collins 75A-3 with the 148C-1 Foster-Seeley discriminator option if I want to use tube-type equipment. Otherwise, for 10-meter FM I usually use a Pathcom/PACE Landmaster II base station.

When I use my Hallicrafters HT-20 it is used with my Collins 75A-2 and that is usually on 160-meter CW. For the HT-20 VFO I usually use one of my Heath VF-1 VFOs but I also have a WRL 755 VFO that is actually better than either of the VF-1 VFOs. For 160-meter SSB I use my Hammarlund HX-50A with my 75A-4.

Anyway, there has been no further information about the dates of the HT-20!

Glen, K9STH