In Construction!BOAT ANCHORS

In Construction!

 

Older pieces of equipment, especially heavy ones with tubes, are often referred to as boat anchors.

Well, they may hold a boat from dragging, but they can also "hold their own" as comes to intended performance.

We will start out with a couple of small tubeless ones, for surfing boards or canoes I guess.

 

On top is an UHER tape recorder, for 5" spools. It has 4 speeds and is a good performer. This particular one is equipped with an automatic level control of the recording. I am not sure I like it, but it can be de-selected. It also has an IC for the audio output amplifier. This is a definite improvement over the older ones that used a complementary pair of Germanium transistors. I have two more of these recorders, and in one of them I had already made this modification, replacing the audio amplifier with an IC, before the one above appeared on a flea market. 11 lbs. (5 kg) with 5 D-size NiCd batteries.

The four speeds is a very nice feature. They range from 19 cm/s to 2.4 cm/s. It is interesting to record high pitch sounds from crickets, humming birds, bats and listen to it at a lower speed. That is why I have three of these babies!

Below the recorder is a "Frog-7" (Yaesu FRG-7) which is only slightly heavier than the Uher. It is a quite all right receiver, covering 0.5 ~ 30 MHz in 1 MHz bands. It has the interesting Barlow-Wadley Loop design, where the signal is mixed up to a high first IF, around 52 MHz, and then mixed down again with the same oscillator, so drift is cancelled. Remains the VFO, which is very stable. Another good feature is the pre-selector. A tuned circuit on the input that keeps out most of the strong signals all over the band that otherwise would overload the input circuit and create intermodulation products. 16 lbs. without battery and 22 with a gel cell battery I have in it. 7.3 and 10 kg respective.

Next some tube equipment! Let us start out with the right, light, stuff:

 

The Swedish surplus commando troop HF station RA 190. Above left, the receiver. To the right: the transmitter. Crystal control only. A little Morse code key is built in under the instrument. Below to the left A view of both. The filaments runs on 3 Volt from four D-cells. I have built a dual DC-DC converter replacing the 2 x 67.5 V anode batteries. It is smaller than one battery.

Total weight: a few kg.

 

Tandberg Model 2 tape recorder.

A nice old, and well functioning, tape recorder, made in Norway. Would you believe it!

21 lbs. = 9.5 kg.

 

I even have the special tools, and the service manual, for adjustment and work on these tape recorders! It ought to be a pretty unusual kit. è

Among most Swedes (and Norwegians, I am sure) of my age, this is the recorder we all recognize as the one Swedish schools had for language classes. As a matter in fact, Tandberg got a bit cocky about this. I was involved in the design and construction of the audio system for the new City Library in Göteborg in the mid -60s. Tandbergs equipment was already designed in by the architect. Selected by default!

 

 Tandberg refused to give any discount for the pretty big order of recorders, loudspeakers and what have you. They said: "We will sell them anyway." These words made us look for someone else. Braun, the German manufacturer (called "Krupp" in the US) has even nicer equipment, but also more expensive. The contractor sacrificed his profit from the project and Braun went down to their own cost, so this way the equipment came down to Tandbergs price, and the library ended up with the Braun equipment. And Tandbergs Swedish representative learned a lesson.

 

 

 

Grundig, good old German radios with good sound! Both has "equalizers" (the four central controls on the keyboard) and they are from about 1957. Both also have a ferrite antenna that can be rotated from a knob on the front. This way interference on AM can often be zeroed out. The grammophone console to the right has a push-pull final amplifier with EL90's and five loudspeakers. Two electrostatic. Unknown weight…so far!

 

SRA (Svenska Radio Aktiebolaget) built this one. It covers from 50 kHz to 500 kHz in two bands and 1500 to 4500 kHz on a third. For marine use. It was designed for operation at some 60 - 90 V DC, but I built in a power supply. I also built in a S-meter. With the tubes used, ECH 21, one of the best mixer tubes ever designed, the S-meter give a linear deflection over a 70 dB range of signal strengths. The peculiar thing about this receiver is that all five tubes are ECH 21! Anyone can change tubes! At the right side of the front panel is a wave trap, covering 1.7 - 3.4 MHz, so the receiver is not de-sensitized by transmission while listening to a nearby frequency.

32 lbs. 14.5 kg.

It is very well shielded in a sheet metal box, so I have used it for a bridge detector as well. In the late 70's I even heard an emergency call on the 500 kHz frequency. It was from a ship in a storm out on the North Sea. The coast radio station heard him also, so it all went OK. At least they listen to the emergency frequencies in civilized countries. The 500 kHz is shut down now. Try 2182 kHz (emergency and call-up frequency) in Gambia! I have, and you can call all day. Their "Minister of Marine Affairs" (1973) is a cocky SOB, and he sure did not get the job on any competency of his. Neither did the President by the way. It is not the place to get shipwrecked!

The SM6CVV call used to be mine. As I moved, the telephone company did not forward the annual bill and I lost the call. Since they are the same bureaucracy, even the bills looks identical, one would think that they could handle it, but bureaucracy is the key word. One cannot expect too much service for only $40/year…

 

A beautiful anchor from the mid 30's. The National HRO MX. This receiver is quite a performer even 60+ years later. To the left, with some of the 12 coil systems (they plug in like drawers) and the "doghouse" power supply to the right. The drawers to the left are general coverage, about one octave each. There are 8 of them, covering 100 kHz to 30 MHz but for just around 455 kHz, the IF frequency. The drawers to the right are also general coverage, but move a couple of screws from one hole to another and they become bandspread coils for the amateur radio 80, 40, 20 and 10 m bands.

On the right picture, a close up of the receiver.The dial knob has a clever mechanism permutating the numbers behind the windows, so there is a 500 units scale length.

 Receiver with one drawer, but without power supply: 35 lbs. 15.9 kg.

 

This innards of this beautiful performer. The box to the right, near the front panel, contains the crystal filter for CW (Morse Code).

The receiver has low noise, good selectivity, good sensitivity, low intermod and tubes that glows in the dark!

I bought this beauty from a surplus dealer in London around 1974, in the summer, for about £70. It has stayed with me ever since, and will continue to do so for as long as I can help it.

Anybody coming across this page knows him? I do not remember the name and address, but it was pretty much in some "Surplus District" of London. Around Earls Court? His business was in a building, wood as I remember, with an extra floor halfway to the ceiling in part of a fairly big room. This floor construction was definitely wood. Let him know that the receiver came to a good home and has logged many hours of enjoyable listening!

 

 

The ultimate boat anchor, at least in the receiver business. The R-390A/UUR

I think the manual mentions a weight of 85 lbs. (38.6 kg) and I believe it.

This one, in a nice steel cabinet, is actually 110 lbs. (50 kg!)

The right picture shows the view from above. One can barely see the very complicated gear mechanism on the upper left. I may take a picture of it by itself from the manual. This receiver is the receiver to top all receivers. The Collins mechanical filters are phenomenal. One can listen to either sideband of a local AM station without hearing the carrier!

I have two of these receivers. The one in the picture has some history. It was one of two onboard Greenpeace's M/S "Save the Whales" as they went to New Zealand to get sunk by a bomb. Before they sailed they left this one in Los Angeles for overhaul, and they never came back to claim it. Too bad on the other one that went down with the ship. Now this one works great, though. It is built by Motorola on order 14-PH-56, S/N 2952. The careful observer may notice that the knob usually named BFO ON/OFF here has four positions. The extra two are LSB and USB! Just inside the panel is an extra tube and a X-tal oscillator at 455 kHz +/- 1.3 kHz. Very nice.

 

The schematic diagram of the mechanical gears in the 390…. And the block diagram of the gears.

More stuff than in a chronometer!

 

The filter performances (16-8-4-2-0.1 kHz wide) and the ballast tube characteristics.

Here: the filter performance as I recorded it with a pretty provisorical setup I made. You can see the 16 kHz (the widest) filter being almost 10 dB down from the 4 kHz filter. Guess I have to look into that one! You can also see the 4 kHz filter drop some 80 dB over less than a 1 kHz! The raised bases may very well be residual noise in my generator. One can also see that the crystal filter seems to couple to the 2 kHz filter at -40 dB.

I also looked into the characteristics of the ballast tube, once I had it all apart. I had heard a lot about the difficulties to get a replacement. It seems to me that a constant current source of 300 mA would take care of it. A diode bridge, and a power MOS FET with constant -Vg, properly adjusted, ought to do it as well. The picture on the right reflects the measurement of the ballast tube I-V characteristics.

 I have a second receiver of this kind as well, and it works so-so. More for spare parts. It is built by Capehurt Corp. S/N 10007. With a serial number like that I do not think they built very many, but I may be wrong. This one is without cabinet and weighs in at only70 lbs. (32 kg).

 

The TS-510 A/U signal generator is a good boat anchor. With case it weighs 43 kg (95 lbm) and without it only a skimpy 27 kg (60 lbm).

The shipping box, accounting for the difference in mass, is of as good quality as the generator.

This generator is built by "Winslow Tele-Tronics Inc. From what I heard nobody but HP ever managed to build a RF module that worked. Once HP won the first contract they had to give up schematics and drawings over the design. For the next purchase the Government went for the lowest bidder. It was not HP. Whoever it was found out that RF truly is black magic. They had to buy the RF modules from HP who at this point were not shy about how much they charged! Rigtly so.

 

 

Power supplies can be major boat anchors! This baby, with 48 kg (105 lbm) is a worthy representative!

It also delivers 0-2.5 kV and 400 mA.

Not under water though.

 

Back to a few more reasonable sized instruments:

 

On the left a Boonton Q-meter and on the right the Boonton RX-meter.

At 11.3 and 16.3 kg (25 and 36 lbs) they can hold midsize vessels.

The 1308A by General Radio is a major anchor with 41 kg (90 lbm). Not a very big instrument, good density! It is a 400 W audio amplifier with a built in generator. It can deliver the power at 20 Hz to 20 kHz into loads from a few Ohm up to several hundred Ohm.

 

In the mechanical equipment department I have a lathe that I have not put on the scale, but how about:

the OMT rotary table? 34 massive kilo (75 lbm) of cast iron. Under the table is a glass dial and in front a microscope for readout.

This dial allows settings to within ¼ minute of arc, 1/240 of a degree. It is the angle of one meter as seen at a distance of 13.75 km, or of one inch at 380 yards. Big roller bearings enables this table to hold several tons.

 

The Rosa bench drill press. Not a good picture, there is a table behind the yellow box also. It weighs in at 98 kg (215 lbm), enough that I barely could lift it up on the table.

A beautifully running machine. Thin flat belt, DC motor with variable speed and almost no vibrations.

This may not be the end of it!

Check in soon again!