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I've finished testing my modification for providing a CW offset when running the HT-44 and SX-117 in transceive mode under control of the receiver VFO. This is a "no-holes" modification that's inexpensive to implement and provides true CW transceive operation. In other words, with your slide switch in XCVR position, you can tune the receiver to a station and call him and you'll be zero beat with him (or very nearly). Without the modification, using transceive mode on CW is useless as calling a station you hear results in you being off his frequency by a difference equal to the frequency of the tone you're listening to. The circuitry resides on a small board mounted near the VFO capacitor leads under the SX-117 chassis. A cable between the HT-44 octal plug and the RCA jack labeled ANT on the SX-117 connects the circuit to a N/O relay contact in the HT-44. When the HT-44 goes to transmit, the relay causes the SX-117 VFO offset to occur. The mod does not affect the stability of the VFO and is easily removed. When operating SSB in transceive mode, you unplug the cable mentioned above and then the offset does not occur. Schematic follows. Probably unreadable and no way to increase the size here, so if interested, let me know and I'll email it to you. 73, Floyd - K8AC

Hi all, Digging in old museum papers sometimes provide some interesting views to the past. See attached. The prices are in 1959 Canadian dollars. Payette Radio was the biggest consumer/industrial electronics supplier in eastern Canada then. 73, Jacques, VE2JFE in Montreal

Hello all. I am excited to have found this group. My callsign is W6BPT. I recently acquired a hallicrafters ht-45 loudenboomer. I did the initial tuning via the downloadable manual and the amp works great. My question to the forum is this: Is there a writeup only on the tuning of the amp. I was hoping for something like this so when I go from 40 meters to 20 to 15 it would be a quick reference for quick tuning. Thank you and 73's Brian

Hello all, I am a new member to the group but have been a HAM for awhile now. My main station now is a tentec omni VI with a HT45 amp. My callsign is W6BPT. I am looking forward to talking with everyone and I hope to chat with you on 15,20, or 40 meters someday. 73's and Semper Fi Brian

Anyone seen one like this? I bought this off eBay years ago and it's been sitting in a box until yesterday. Took it out for a look and was surprised to find that I had two more tubes than shown in the manual or schematic. And a large box mounted as shown in the picture with a 6AG5 tube on it's top and a cable running from the box to underneath the chassis. There was also an extra IF looking transformer and an additional 6BA6 mounted between the new trans can and the existing one. I can barely make out, scratched into the top of the box, 6M Preamp and some voltages, I'm guessing are what the cable has to pick off from under the chassis. Tested the tubes and brought it up on the variac and Dim Bulb. Dial lamps light up but no audio (or smoke). Haven't started troubleshooting yet as I got sidetracked with the extra tubes and transformer, not to mention "The Box". Any insight on this? Thanks, K8NN

The VFO in my newest HT46 has excessive drift. In standby mode it will drift about 1KHz in the first 15 minutes and then go another 600Hz in the following hour. The VFO drifts downward in frequency so it appears as though the capacitance in the tuned circuit needs more NEGATIVE temperature coefficient. It has a 10pfN750 and an 82pfN80 capacitor for compensation but they aren’t quite doing the job. Following some work by W7ZOI I have experimented with some different series combinations of N750 and NP0 capacitors in place of the 10pfN750. I have reduced the drift to about 10Hz/C but the series combination that produced that adds too much total capacitance to the circuit so it is not a solution. Experimental results and a few calculations would indicate I need a 10pfN1285 capacitor but of course that will be difficult to achieve. What bothers me about all this is that I have two other VFOs of this design - one in an SX146 receiver and the other in an old beat up and abused HT46. Both those VFOs have negligible drift. I have checked and re-checked the components in the offending VFO and I have compared them to what is in the well behaved HT46. Hopefully someone has experience with this or knows about a common cause for such behavior. 73 – Jerry – W0PWE

I’m going to build a switch/outlet power box to turn my Harmon-Kardon audio amplifier on/off. I have been using the switched output of my receiver. My question is: Is there a simple circuit to ramp up the 120 v ac ? My thinking is that might be easier on the KT-88 tubes in the amplifier. Or is it unnecessary? Skip Magnuson W7WGM

Still cleaning out cabinets. I have a transformer and cannot remember what it goes to. It has a Hallicrafters part # 050-004270. It has another number that may be a manufacturer's in-house part # or it could be a date code 5247120, perhaps week 20 of 1971???? I have a hunch it may be for one of the SBT rigs. Any good ideas out there????? Walt Cates, WD0GOF https://wd0gof.com/Hallicrafters A majority of acceptance is not proof of correctness. https://wd0gof.com/bible-study/commentaries/

G'day y'all. So the SX-16 was wrapped up, just about, with the bottom cover put back in place and a final IF/RF alignment done. Spent a good part of last evening SWLing and tuning in 20M and 40M SSB rag-chewing. Next day I fire it up and there is an awful loud cacophony of snaps, crackles and pops emanating from the speaker. The level of that csp does not change with AF or RF gain control, just as loud with both turned to minimum. Other than the csp noise all functions operate as expected, even the top two bands pull in CB'rs (oh joy!) and 6M SSB on just the test bench long wire. Yes, a complete electro/wax/mica cap replacement had been done, any resistor over or approaching 20% out of spec replaced, etc, etc. Monitoring the B+ it seems a steady 310v DC after a short warm up. (Variac is at 115vac.) I swapped the 5881's (that it came with in place of the 6V6G's), swapped the 6R7 (as it's the first audio amp), no change. With the 2nd IF amp 6K7 removed the noise is still there confirming it's after that (or supply related). I even pulled the cover off of T4 to look at those top mounted trimmers, very clean and looked fine to me. (Even tho it sort of resembles that kind of noise, I usually don't suspect an SMD issue with such trimmers anyways.) Went after a couple of the remaining ceramic picofarad caps around the AVC/1st audio section, no change to noise. (The SX-25 developed same issue after a year's use and that was a mica I had left in that same area.) Voltage checks are within those listed on the SX-16 chart with the exception of the screen voltage on the 5881's, pin 4 is at 290v where the chart shows 275v for a pair of 6V6's. But the 5881's have a higher screen voltage rating anyway. The amount of noise seems to lessen after the receiver is left on awhile but never lessens in volume or goes away. I dread it being one of the audio transformers but could it be? Searched this forum and I found Bill's SX-17 posting with apparently same issue but could not find any follow up to it. So, Bill, ever resolve? (oh please, oh please have a simple fix!) I'm all ears to any suggestions. -- Dan K1DTS

There is any one with a Hallicrafters A-84 ? This was my first Hi-Fi amplifier when I was 16, and always wished to listen to a pair. Only 10W with a pair of class A biased, triode-connected KT66s in the output, but it was giving a run to the Quad IIs of the same vintage. If you have one collecting dust, please let me know. 73, Jacques, VE2JFE in Montreal

I was recently given some ham related books. In one I found a 1964 16 page (3-1/2" x 8-1/2") Hallicrafters flyer that was being used as a book mark. The flyer title is "Short Wave (Plus Local Broadcast) Receivers". I scanned it, cleaned it up and put it up on our club website. The URL is: https://www.w6ze.org/Items/1964%20HallicraftersFlyer.pdf Thought it might be of some interest to members of this group. Feel free to add it to the group files if you'd like. Cheers, 73, and Happy Thanksgiving, Bob, AF6C

Shipping at buyers expense is now available via The UPS Store Downsizing. For Sale my Hallicrafters SR-150 Transceiver, PM-150-120. power supply and copy of manual downloaded from the internet. I purchased the SR-150 and power supply at a hamfest in Florida about three years ago and they are in excellent physical condition with some paint chips on their cabinets. They were both recapped by someone else previously. They have been used sparsely by me. I am downsizing my station in anticipation of moving to a smaller QTH. The SR-150 transmits and receives well. Some of the controls are a bit scratchy and could probably use a cleaning. Grabbing the cable between the radio and the power supply and twisting it will while the transceiver is powered up will occasionally blow the fuse in the power supply. This does not happen during normal operation. Although they are currently operational, they are nearly 62 years old and they are being sold as is with no warranty expressed or implied and no returns. The Price for everything is $325.00 picked up at my QTH in Highland Park, Illinois. (25 miles north of Chicago, 30 miles south of Wisconsin line.) The price for this equipment is far below what people are paying for units listed as "parts only-not operational" on eBay. Payment is by USPS Money Order only. Please do not contact me and make an offer below $325.00. Price is firm . SHIPPING. After I receive payment, I will take them to the local UPS store after you contact them and make arrangements and agree to pay them for shipping. I don’t have the proper boxes and materials to safely ship them. Please email with any questions. My email is good on QRZ.com. Thank and 73, Ron Harroff K9RH

I wonder if anyone has looked at a modification to the HT-44 to provide a CW mode offset in transceive? I tried adjusting C1 in the HT-44 to get an offset in the area of 500-700 Hz, but could get it up to only about 200 Hz with minimum setting of C1. 73, Floyd - K8AC

I have the twins connected with the SX146 slave output feeding the HT46 injection port. This works great on SSB but on CW there is no offset so copying the other station at zero beat is a little unpleasant. I could set the BFO for a beat note but then I will be off frequency on SSB. I must be missing something obvious here. I know other Hallicrafters twins can be operated this way so maybe someone has a solution. The HT46 oscillator takes a long time to stabilize and it is a little chirpy. Transceive operation with the SX146 oscillator solves that problem but creates another challenge.

I am working on restoring an S-38E and would appreciate a clear reworked copy of its schematic diagram. I have found some scanned copies but none are clear enough to read all of the component values and wiring connections. Thank you all in advance. -- Glen Jenkins, WB4KTF, S-38E wb4ktf@...

The CW knob on the S-38 I just bought is missing. Is there anything special about that knob, or is it the same as the others? I see that the shaft has threads unlike the others. thanks, Fraser, W3UTD

Hello to the group and thanks to the owner for allowing me to post. Today when visiting a Vintage wireless meeting, I picked up a battered Hallicrafters TW 2000 from the estate of a deceased member. I would like to ask a few questions if I may, mainly on cosmetic items? The radio is missing the front wrap cover, which obviously did not help it as the radio had taken a big knock on the front brass bezel just on the writing of 'Dynamic Tuner' and this smashed the glass into several pieces, the brass has been straightened the best I can, and plan to use a piece of acrylic sheet to replace the glass. The plastic section at the bottom of the radio that has the wording of Band selector Tuning Off On Vol, has what looks like aluminium foil on the front edge, is this meant to be what is covering it or is this a replacement for something else already damaged. Perhaps the picture below will help in this description. It is also missing the 'Skyrider antenna'. I am assuming that this is basically a copy of the internal ferrite antenna, but has a small trim cap rather than the 22pF and is fitted into a plastic tube with a few rubber suckers to stick on a window. I know it is not really needed, but if I get chance at some point I could always make up a replacement so if anyone can confirm if it is the same I would appreciate it. Power has not been applied to the radio by me yet, I plan to replace the Hunts tubular paper caps and check the main smoothing caps before any power is applied. Lastly, it has the Ballast Adaptor fitted to allow for 220 Volts AC and has already got a 240 Volt mains plug fitted so I assume the slightly higher voltages we have in the UK should not matter as it stands, I will build up a battery pack for it initially at 90 Volts and 9 Volts and when happy will remove the ballast and fit a 240 to 110 Volt isolation transformer, it should save on a bit of heat within the radio case. Cheers Adrian G8UGD

?While following Glen’s S-38e topic which we hijacked for S-40’s discussions, I came upon the S-38B manual on BAMA which shows and lists PL-2 plug in the AC line cord, and SO-1 on the back of the chassis The manual picture shows SO-1 on the chassis rear apron right side [rear view]. . I could not see these on other versions. Perhaps that was UL’s first punch at safety? So I wonder if there are really there on the B? And is there nothing equivalent on C,D,E? or maybe the back cover carries the equivalent disconnect, but is not shown in the schematics?.. or what ? -- don va3drl

Downsizing. For Sale my Hallicrafters SR-150 Transceiver and PM-150-120. power supply. I purchased the SR-150 and power supply at a hamfest in Florida about three years ago and they are in excellent physical condition. They were both recapped by someone else previously. They have been used sparsely by me including this morning. I am downsizing my station in anticipation of moving to a smaller QTH. Although they are currently operational, they are near 60 years old and they are being sold as is with no warranty expressed or implied. The Price for everything is $325.00 picked up at my QTH in Highland Park, Illinois. (25 miles north of Chicago, 30 miles south of Wisconsin line.) Once picked up there are no refunds. The price for this equipment is far below what people are paying for units listed as "parts only-not operational" on eBay. Payment is by USPS Money Order only. Please do not contact me and make an offer below $325.00. Price is firm, non negotiable. NO SHIPPING for this equipment. It has survived 60 years and I would like that to continue. Please email with any questions. My email is good on QRZ.com. 73, Ron Harroff K9RH

Sent a couple of messages that did not come through. Being moderated for some reason? Or some problem. See if this gets through -- Richard Knoppow Los Angeles WB6KBL SKCC 19998