Home > Uncategorized > Going Vintage- Part 1- My Latest Projects- A Hammarlund HQ170 Receiver and a Johnson Viking Ranger II Transmitter

Going Vintage- Part 1- My Latest Projects- A Hammarlund HQ170 Receiver and a Johnson Viking Ranger II Transmitter

I’ve slowly been drifting towards a vintage radio shack and an interest in restoration of radio history. I began with a Yaesu FT101 and then a Yaesu FT101E, I then restored a 1936 Pilot MW/SW receiver. Recently I had a real desire to operate AM and CW using vintage valve equipment. With that in mind, I sought some vintage gear that I could use to build an interesting station. I first began looking at receivers. I loved the look of and the quality of the Drake receivers, but I wanted a bigger lump of metal more reminiscent of the 1940’s and 1950’s receivers, and one with a lower price tag. I settled on the much larger Hammarlund series of radios, and was able to pick up a Hammarlund HQ170 for a reasonable price. The sales blurb said ” I turned it on and it lit up.” Many of us with experience of old valve equipment would much rather hear you had not turned it on but instead used a variac and current limiter for a few days then finally fired it up on full power. “I turned it on and it lit up” is actually not a good selling point for vintage equipment, except to say that the capacitors at least lasted that long- maybe.

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Now the Hammarlund HQ170 is not an ideal choice for AM reception, but I like a challenge. It used a “new” negative feedback system that had as its goal, the preservation of sound quality at low AF gain. Later on this would cause me a few issues.

When the Hammarlund first arrived I set about examining it for paper capacitors and anything likely to fail. I found only ceramic and mica capacitors except for the main filter capacitor which I tested for leakage using my Eico leakage tester. I decided not to change this capacitor because it is a bit of an oddity and will be difficult to replace with something aesthetically pleasing, though I know I will have to.

The receiver uses 110 V AC supply and at the time of the arrival, I did not have a variac, so set about constructing a power supply from an old Yaesu FT101B main transformer. I also constructed a light bulb current limiter, and ran the Hammarlund on that for a while, changing wattage of the light bulb as I grew in confidence, that the magic smoke was not about to escape.

I made a job list of things I would like to fix, but many of them would have to wait for a later date or perhaps never be done. They included

– replace discoloured perspex indexing- I now know very difficult and will not do this

– replace blown dial lamp- GE No 47.

– replace filter capacitor

– full alignment.

From the moment I turned the receiver on, I was impressed with its sensitivity. I could not wait to get it on a better antenna.

Over the next few weeks I used it to listen to a few nets and some DX and found it an excellent receiver. When I attempted to use in on AM though, I found it quite deaf.  I investigated possible causes and now believe  a weak tube is to blame, but have not yet examined that, preferring to order a new tube before examining things further. Thanks to Rodger WQ9E for the advice.

“Check that the noise limiter switch is off and cycle it a few times to clean, I have run across odd faults in receivers related to these clipper type noise limiters. You could try a different 6BV8 if you have one, it could just be a weak tube here. Check voltage readings at the 6BV8. I recall finding an open L10 in one HQ-170, due to part manufacturing defect (poor solder joint) and not caused by another receiver fault. Of course also check/confirm the three sets of contacts for switch S7 that should show continuity in the AM mode position are making good contact.”

I hope to fully examine the weak AM issue shortly.

A week or so after first firing the Hammarlund up, I chose to do a full alignment. The HQ170 is triple conversion, and the third IF is 60 kHz, but for some reason I mistakenly did the alignment at 65 kHz, so had to redo it a week later. The alignment procedure is very well documented on youtube in multiple parts- whereas the service manual is hopelessly inadequate.

One interesting issue that arose, came about when I used the receiver to monitor my own CW signal.

I noticed as I keyed my transmitter, the received signal “moved” on the 170 so I had to retune with the vernier to monitor my sending. I discovered that this is due to  the designers applying AVC voltage to one of the mixers, resulting in pulling of one of the coupled oscillators with the much higher AVC voltage encountered when monitoring your own sending. Removing the AVC voltage from the mixer fixes that problem. I came across this solution after noticing that the pull changed as RF gain was changed.

I hope to have these radios on active display (being used) for the AM and CW on Anzac Day event.

More about the Hammarlund HQ170 and Viking Ranger II in Part II.

VK4MDX

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Categories: Uncategorized
  1. James Michael Hiney
    August 2, 2016 at 5:34 am

    Is this just a real interesting coincidence? This pair of radios was the standard set up in the Los Angeles city schools during the 1960’s!
    They were in middle school and high school electronics shops. I spent most of my senior year at North Hollywood High school operating the ham radio in the electronics shop! That’s my Novice station and I have duplicated it at home in the 1990’s. Unfortunately I lost the equipment in a fire! That set-up is what taught me how to run HF and appreciate the intricacies of narrow bandwidth and noise and separate transmitter and receiver operating!

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