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member - Wednesday, December 14, 2011 at 17:17:06
Eddystone EB35 Mk.II Vintage: 1970.

For all intents and purposes, identical to the Mk.I, but with a re-styled case.
Interestingly enough, this model has the accolade of being issued with a NATO Stock Number: 5820-99-523-7337.

As with the Mk.I, commonly found amongst Eddystone collections.

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Photo. & comment submitted by Al. (Skywave); Dec. 14, 2011
member - Wednesday, December 14, 2011 at 17:07:49
Eddystone EB35 Mk.1. Vintage: 1965 - 70.
General coverage, broadcast, AM / FM.
Battery pack or optional a.c. mains unit; integral 'speaker.
13 transistors; 6 bands: 150 - 350 kc/s; 550kc/s - 22 Mc/s; 88 - 108 Mc/s.

This is a fairly common model amongst collections of Eddystone Radios.

► Maintenance note: Later models had an extra I.F. stage for F.M.

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Photo. & comment submitted by Al. (Skywave); Dec. 14, 2011
member - Tuesday, December 13, 2011 at 18:20:21
Supplementary note to the above.
Most AR88D receivers were built without the S-meter. In fact, the manual gives electrical and mechanical details of fitting one retrospectively, with the added comment "when, and if, such a meter becomes available". Consequently, many are the number of AR88 receivers that have had an S-meter subsequently fitted by their owners. In the photo. above, although it's difficult to be sure, (sorry about the poor picture),to me it looks like an RCA original.

------------------ Al. / Skywave / Dec. 14, 2011 -----------------------------
member - Tuesday, December 13, 2011 at 13:23:17
Re: above comment & photo.
Both submitted by Al. (Skywave): Dec. 13, 2011
member - Tuesday, December 13, 2011 at 12:42:09
Eddystone EA12, vintage 1964 - 1969.

Eddystone's flagship product for the Amateur Radio market for the period stated.
The design is derived from the 830 series, but the EA12 has a crystal-controlled first oscillator and a tunable second osc. It features nine bands each of 600 kc/s in width: 1.8 - 2.4 Mc/s; 3.4 - 4.0 Mc/s; 6.9 - 7.5 Mc/s; 13.9 - 14.5 Mc/s; 20.9 - 21.5 Mc/s; 27.9 - 28.5 Mc/s; 28.4 - 29.0 Mc/s; 28.9 - 29.5 Mc/s; 29.4 - 30.0 Mc/s.

The 1st. I.F. is tunable over the range 1.1 - 1.7 Mc/s, (local osc. tracks on the low side, 1.0 - 1.6 Mc/s), thus producing a second I.F. of 100 kc/s. This section features a crystal filter, a (very effective) slot filter (rejection exceeds 40 dB) and continuously variable selectivity. Followed by a (very stable) BFO / product detector (based on an EK90) and A.F. filters; a separate detector for A.M. and a noise limiter. A crystal calibrator (100 kc/s) is included. The H.T. is supplied by silicon diodes.

In a nutshell, everything the highly-discerning Radio Amateur could wish for in a communications receiver! A study of the very well written technical & user manual lists a performance spec. which is equally impressive.
Overall, a fine comms. radio for the Radio Amateur, which whilst expensive in its day, still commands a very high price in the S/H market, when one does appear - and that itself is infrequent.

► Operator's notes.
The tuning dial, at first, can strike you as a rather strange, since compared to many receivers, the dial calibrations go the 'wrong way'. But you soon get used to this, and the size of the dial window and the ease of accurately measuring the freq. of the received signal more than compensates for this, which is a by-product of the tuning arrangements.

► Maintenance notes ~ based on my experience of the EA12 ~ which may not be applicable to yours!
The few that have passed through my hands (and bench!) have required little work in this direction: usually a question of measuring that the performance is up to spec. and adjusting as required. Having said that, on account of the complex nature of the tuning arrangements, it is absolutely essential that the technical manual is studied thoroughly first and that the concept of those tuning arrangements are completely understood, prior to any 'tweaking'. Even then, recourse to the manual is necessary to discover / remind oneself of just what the appropriate frequencies are - and why and when. A methodical method is necessary, as is the use of quality test gear.

Having said all that, on several of the sets I have worked on I have found that a series of weak - and not so weak - 'birdies' do appear on the lowest freq. band. And I have had confirmation of this from some other EA12 owners. In actual point of fact, they are not that troublesome, since you know they are there and get ignored. The cause I have never unquestionably determined (despite much effort), but several theories do abound.
member - Tuesday, December 13, 2011 at 10:57:46
The Hallicrafters SX28(U) The receiver shown is usually known as the U variant as its mains transformer is adjustable for 115v or 230v operation, the SX28 was used by armed forces and government departments during the war including listening stations hear in the UK, as well as being used in amature radio circles. The SX28 was quite an advanced receiver for its time, it employs 15 valves including the rectifier and covers from 550 Kc/s to 43 Mc/s in 6 bands it has three selectable IF band widths and three selectable Xtal filter band widths the latter used in conjunction with the Xtal phasing control. The receiver has its own seperate AGC and Noise Limiter amplifers, both the AGC and the Noise Limiter work very well on these receivers if serviced and aligned correctly.
Plenty of audio in these, the receiver uses two 6V6's in push pull driven by a 6SC7. The receiver is single conversion employing an IF frequency of 455 Kc/s provision is made to operate the receiver from an external power supply source.
The one shown has been a bit of a labour of love and there is still more work to do to it, mainly cosmetic, it has had 95% of the capacitors and resistors replaced during a recent overhaul, the receiver is all workie workie and is shown receiving amature radio transmissions on the 40 meter band, both sets of tuning mechanisms run very smooth after a recent gearbox overhaul and run in, the band indicator fingers behind the dials have been restrung of late and now function properly.
Out of the many Hallicrafters models that were produced I reckon this one is there all time classic.

Lawrence 13/12/2011.
member - Tuesday, December 13, 2011 at 10:22:01
I do like the look of that radio :like: ~ its front panel looks so 'business-like'!
Al.(Skywave), Dec. 13, 2011
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member - Tuesday, December 13, 2011 at 09:41:22
Eddystone S.640
Dates from circa. 1947 - 1949. (Photo. is from my collection.)

Gen. coverage S.W. comms. receiver, 1.7 to 31 Mc/s. Octal valves; electrical bandspread; 1 R.F., 2 I.F. (1600 kc/s), crystal filter; BFO. A.F. O/P is a 6V6G on its own sub-chassis.

As with many of the earlier manufactured Eddystones, the growth of technology since has tended to render these earlier sets somewhat inadequate to cope with the prevailing conditions on today's S.W. bands - and the S.640 is no exception to this, especially when one considers the I.F: 1600 kc/s, although this does help towards obtaining a better image rejection ratio than if the I.F. chosen had been in the range 400 - 500 kc/s (with one R.F. stage). However, after restoration and re-alignment, on mine I measured an IRR of about 40 dB @ 28 Mc/s; the original spec. is 45 dB.

► Maintenance note.
Briefly, fairly straight-forward, although like all Eddystones, component replacement within the central coil box is difficult.

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Photo. and comments by Al. (Skywave): Dec. 13, 2011
member - Tuesday, December 13, 2011 at 09:21:17
Eddystone 888A.
Pre-WARC Amateur Bands only double-conversion s/het., derived from the earlier G.C. model, the 750. The 888A dates from 1957 - 1961. Only a few hundred were built.

Uses 11 valves - all miniature types, except for the two in the PSU.
1 R.F, 1st. mixer (1st. I.F. 1620 kc/s), 2nd. mixer, 1 I.F. (85 kc/s), continuously variable bandwidth, product detector, noise limiter, crystal calibrator (100 kc/s), audio filter (C.W.); AGC switchable, separate I.F. and R.F. gain controls.

An expensive set in its day and, in my experience, performs very well when compared to more modern receivers of its type: AmRad Bands only. The fitment of only 1 I.F. stage could cause some concern, but since that stage runs at 85 kc/s, the overall gain of the set is more than adequate.

► Maintenance notes.
As with many Eddystones, maintenance is not a trivial matter, mainly because the beneath-chassis areas are very densely packed with components. Fortunately, once this set has been brought up to spec., it does tend to be relatively trouble-free from that point onwards. During 35 years of ownership, I have had to replace only a few R and C; one VR150/30; three ECH81 1st. mixer valves and one 6BE6 in the prod. detector. As with all Eddystone radios, a routine check on valve electrode voltages and R.F / I.F. alignment - say once every few years, depending on operating environment - keeps it in top shape. Am I going to part company with mine? A decided "No!" is the answer!

► Buyer's note:
The earlier model was the 888. The main difference is that the 888 features a traditional BFO, instead of the product detector as in the 888A. Every 888 I have seen has a black case; every 888A I have seen has a grey hammer finish case, but there may be exceptions to this 'rule'.

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Photo. and comments by Al. (Skywave); Dec. 13, 2011
member - Tuesday, December 13, 2011 at 08:50:12
Eddystone 840A.
[Photo. shows mine prior to restoration.]

Derived from its predecessor, the 840. The 840A dates from 1954 - 1961. Approx. 2,000 were manufactured.
Gen. coverage a.c./d.c. s/het. Four switched bands: 480 - 1400 kc/s; 1.37 - 3.8 Mc/s; 3.7 - 10.6 Mc/s; 10.5 - 30 Mc/s.
7 valves ("U" series heaters); 1 R.F.; 1 I.F. (450 kc/s); B.F.O.

A basic S.W. set that, in my opinion, doesn't really fit the description of a comms. receiver. But it is a relatively simple set, so maintenance is usually fairly straight-forward.
There is an interesting write-up on the model 840 (very similar) in Wireless World, August 1953, if you can obtain a copy or a print of that article.

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Photo. and comments by Al. (Skywave); Dec. 13, 2011