User comments

Home / User comments

Filter

Keyword

Author

Album

Since

Display

Sort by

Sort order

Number of items

First | Previous | 1 ... 19 20 21 22 23 ... 25 | Next | Last

member - Tuesday, December 13, 2011 at 07:11:54
Eddystone 730/4.
There were many variants built on the '730' scheme, of which the 730/4 is by far the commonest found. Originally designed to meet a substantial order from the M.O.D. Dates from 1956 - 1962. The basic design is derived from the 680X (q.v.)

Single conv. s/het.; 500 kc/s - 30 Mc/s in 5 switched bands; I.F. 450 kc/s (crystal filter); 15 valves; 2 R.F. stages; good range of user-controls and facilities ~ as is usual for Eddystone's comms. receivers aimed at the professional user. Can be operated from an external d.c. power source.

Photo. above shows mine after restoration; nothing too dramatic was required, except for attention to the jumper plug / socket at the rear. This socket is for connecting to an external d.c. supply. When not that is not required, the jumper plug is inserted. Unfortunately, over time, the pins become tarnished and an open-circuit (intermittent :evil: or permanent) develops, depriving the set of H.T. and / or 6.3 v.a.c.

► Maintenance note: Read the above and don't overlook the 'stand-by' switch which is mysteriously located inside the receiver above the tuning condenser - where the spare fuses and trimming tool are located.

--------------------------------------------------------------------------------
Photo. and comments submitted by Al. (Skywave); Dec. 13, 2011.
member - Tuesday, December 13, 2011 at 06:45:12
Eddystone 680X.
Eddystone's attempt to produce a quality general-purpose receiver with wide appeal for the S.W.L. and Amateur: S.W. broadcast bands and the Amateurs' needs are well-catered for.
General coverage, single conversion s/het. with 2 R.F. stages; I.F 450 kc/s (crystal filter); B.F.O.; push-pull A.F. O/P stage.
5 bands: 480 - 1110 kc/s; 1.11 - 2.5 Mc/s; 2.5 - 5.7 Mc/s; 5.3 - 12.5 Mc/s; 12.3 - 30.0 Mc/s. 15 valves: 13 are B7G, B9A; rectifier and stabilizer are Octals.
A good range of user-controls, including variable selectivity.

The photo. above shows mine after renovation. When first acquired, it had been stored in an attic for many years: it was full of thick dust, cobwebs, dead insects & various small rodents! Most of the necessary work was routine stuff, except for the need to replace almost every B9A / B7G valve socket. This is not an easy task on any Eddystone. When renovation was complete, it was very satisfying to discover that it met - and often exceeded - the published performance specs.

--------------------------------------------------------------------------------
Photo. and comments submitted by Al. (Skywave): Dec. 13, 2011
member - Monday, December 12, 2011 at 20:13:25
FR-50B ~ from Yaesu-Musen (a.k.a. Sommerkamp: Japanese).

Amateur Bands only; double-conversion s/het.
On the band selector switch, the AUX. position is usually wired up for 10 MHz WWV reception, although coverage of the 11m. Citizen's Band is often found here in models sold in the U.S.A.
The set is remarkably sensitive: on mine, on the three H.F bands, I measured about 0.5 µV for a 10 dB S/N ratio. Other bands returned about 1µV: perfectly adequate.

However, as with most of Y-M's early products, it is a mix of quirky and excellent features. And one that is highly debatable: drift of the local oscillator. Many are the users (and ex-users) who categorically state that the medium term drift is really bad. And that confuses me, since mine is exceptionally stable! Perhaps the most baffling quirky 'feature' is the front panel 'CH. SELECT' rotary 'switch' ~ because there isn't a switch there at all! (Well there isn't on mine; the knob was simply secured to the front panel by a humble nut and bolt! And there are no signs that any circuitry for this switch was ever fitted.) It's fairly obvious what it's for: VFO control or fixed crystal-controlled operation.
The mechanics of the tuning control are a bit (literally) shaky, but I easily solved this on mine with an arrangement of an out-rigger bearing and spacers. The resultant smoothness of tuning was comparable to an Eddystone! And whilst I was geared up for that job, I split the combined R.F. / I.F. gain control into separate controls, mounting the new I.F. gain control where the (pointless) MONITOR control was. This gave a worthwhile improvement is controlling the gain distribution. As for the CH. SELECT knob, I simply fitted an antenna trimmer capacitor to compensate for de-tuning the front end R.F. coils when using my 60 ft. 'longwire'. The set has two antenna input terminals: 'LW' and '50-ohm'.

► Operator's note.
As standard shipment from Y-M, the 100 KHz crystal for the calibrator is NOT FITTED! An B7G valve pin-out type is required.

► Maintenance notes.
This set features a "T" notch filter in the antenna input to reduce / eliminate break-though at the 1st. I.F. (which is in the order of 5 MHz). Check its setting with a signal generator. If you find that it won't null, it's not you, or your kit: it's Y-M: they got their sums wrong! :sad: A simple re-design is required: I have retained my notes for this.
R.F. alignment is a very delicate affair! The trimmer capacitors - which are mounted on strips of Paxolin - are not only very critical in their adjustment, but also very fragile - they easily disintegrate! Miniature moving / fixed vane variable caps. can be fitted as replacements, as can 2 - 8 pF 'Beehive' trimmers.
Component layout beneath the chassis is quite good: easy access to components, as is typical of Japanese radios of this vintage.

--------------------------------------------------------------------------------
Photo. & commentary by Al. (Skywave): Dec. 13, 2011
member - Monday, December 12, 2011 at 17:21:45
Icom ICR-7000 (Japanese).

O.K., I will readily accept the criticism that this receiver is a bit 'too recent' to classify as true 'Vintage' - but it has been around for quite some time now and for its type and class, it really is an excellent receiver and is held in very high regard in enthusiasts' hands - and in professional circles as well.
It's an 'all solid-state' fully synthesized 'bells 'n' whistles' scanning receiver with an enormous tuning range: from 25 MHz to above 1 GHz (N.B.: That isn't a typo!). The model in the photograph is from my collection. For what it does and what it is, it really is incredibly small for its size - and that is reflected in the 'density of the packing' inside the case: serious maintenance is a serious challenge! However, one common mode of failure is poor SSB resolution. This is usually caused by failing / failed small-size electrolytic PSU decoupling capacitors. I have retained my maintenance notes for this should anyone experience this fault. (But no guarantees! :sad:).

Hook one of these up to a discone antenna at about 40 feet, and there'll be enough for you to listen to, (or 'monitor', if you prefer), to keep you occupied for ages!

--------------------------------------------------------------------------------
Photo. submitted by Al. (Skywave) - 12 Dec. 2011.
member - Monday, December 12, 2011 at 17:01:28
Realistic DX-160 short-wave radio. Japanese.

The 'Realistic' brand name was used by Tandy. Tandy is the U.K. counter-part of Radio Shack in the U.S.A.
The Realistic DX-160 could be called a 'communications receiver', but to me, it is a short-wave broadcast receiver, masquerading as a comms. receiver. It dates from the 1970's when there were many such-like radios pouring out of Japan. As a S.W. broadcast receiver for the S.W.L. it works tolerably well, except on the highest freq. band where the image rejection ratio above 14 MHz is quite poor.

► Note that the local osc. runs on the high side of the incoming freq. on all bands except this one - the highest. This caused me a great deal of head scratching during re-alignment (I.F. = 455 kHz) when I owned one many years ago - until the penny dropped. To its credit, however, this receiver does have some worthwhile features: cascode front end, excellent A.G.C characteristics, sensible R.F. & I.F. gain distribution and control arrangements, amongst others.

► Warning.
If you find that yours will NOT 'track' on the lowest freq. band, talk to me. I found a major design failing in this department and a serious re-design was required. (Details I have retained). After that 'repair' (which is quite extensive), it then worked 'to spec.' . . . . more or less.

--------------------------------------------------------------------------------
Photo. submitted by Al. (Skywave); Dec. 12, 2011.
member - Monday, December 12, 2011 at 16:37:49
Yaesu-Musen FRG-7. Japanese.

Possibly not exactly 'Vintage' but this model has been around for quite some time now and is still in great demand by enthusiasts. Sale prices can easily exceed £100 for a model in good condition.

Basically, a general coverage receiver using the Wadley Loop principle - as made famous in the Racal RA-17. The above photo. is from my collection, and the eagle-eyed enthusiast will note two differences from standard build:
►(a) The tuning knob: that is purely down to me and my personal taste!
►(b) The 'LOCK' L.E.D. is green. This is a fairly common modification to the FRG-7, and very easily implemented. The basic idea of the L.E.D. is to inform the operator when the 1st. V.F.O. is in 'lock'. By the standard design, when it IS 'in lock', the LED comes ON - and is RED. Otherwise the L.E.D. is extinguished. To me, this is contradictory and confusing. With a teeny-weeny bit of extra transistory and a bi-colour L.E.D., things can be arranged so that IN-LOCK = GREEN; OUT-OF-LOCK = RED ~ as above. Much more logical, captain!

Y-M's products can be a bit quirky, though. Many have been the their products which have been across my bench, and upon close analysis I've often though "Huh? They must have been in a bit of a rush here!" Nevertheless, most of Y-M's products work well, even if a small mod. or re-work is required - and the FRG-7 (affectionately known as the "Frog Seven"), is no exception.

* Yaesu-Musen also trade under the name of Sommerkamp.

--------------------------------------------------------------------------------
Photo. submitted by Al. (Skywave) - Dec. 12, 2011.
member - Monday, December 12, 2011 at 16:11:54
Heathkit model RA-1: Amateur Bands only receiver. 1960's vintage.

In its time, a popular receiver amongst SWLs and Amateurs alike. I owned one during the 1960's and was fairly pleased with its performance, especially considering that it is not a 'high-end' product.

Heathkit (Gloucester) was the U.K. subsidiary of Daystrom (U.S.A.), and as the name implies, you could buy any item from Heathkit as a kit, and build that item yourself. Alternatively, you could buy that item ready-made from the manufacturers. Heathkit closed their Gloucester factory in the early '70's. The ever-increasing influx of products from the Far East made Heathkit yet another victim of this change in the market-place.

--------------------------------------------------------------------------------
Photo. submitted by Al. (Skywave) - Dec. 12, 2011.
member - Monday, December 12, 2011 at 15:58:04
The PCR* comms. receiver. Manufactured in large numbers for the British Army by Pye and Philips. There are several variants: PCR, PCR1, PCR2 and PCR3: most have features in common. It was designed primarily for the reception of broadcast stations*, but has always been popular with S.W.L.s, usually after a B.F.O. has been fitted as a modification.

PCR. (Base model). Valves: 6, (Octals): 1 R.F. stage; 2 I.F. stages; A.F. O/P = 6V6. Contains 5" speaker. Freq. range: 850 - 2,000 metres; 200 - 550 metres; 6 - 18 Mc/s: 'standard domestic broadcast receiver' coverage. External PSU required: 250 v.d.c. & 12 v.

PCR1. Freq. range: 860 - 2080 metres; 190 - 570 metres; 5.6 - 18 Mc/s. Has internal speaker.

PCR2. Freq. range: 850 - 2000 metres; 200 - 550 metres; 6 - 23 Mc/s. Does not have internal speaker.

PCR3. Freq. range: 200 - 550 metres; 2.5 - 7 Mc/s; 7 - 23 Mc/s. Does not have internal speaker.

* "PCR" = Personal Communications Receiver, I have been told, but have not had this formally validated.

Please note.
In the past I have been informed that some of the above data is in error. Please contact me if you can assist in this; above data will be amended as appropriate. Thank you. Al (Skywave). Dec. 2011.

--------------------------------------------------------------------------------
Photo. submitted by Al. (Skywave) - Dec. 12, 2011
member - Monday, December 12, 2011 at 15:35:14
BC348 - as used by the United States Air Force and Army.

Designed to operate from 28 v.d.c. supply; an extremely compact receiver. There are many variations of this receiver: the suffix letter discriminates.
Freq. coverage: 200 kc/s - 500 kc/s; 1.5 Mc/s - 18 Mc/s. I.F. = 915 kc/s.
Uses 8 valves on the 6xx type ('metal' valves), except for the A.F. O/P stage. This is designed to match a load of 500 or 4,500 ohms.

A popular receiver for the S.W.L. in the mid 1950's - 1960's, when there were substantial releases of these to the general public. More common in the U.S.A. than the U.K.

--------------------------------------------------------------------------------
Photo. submitted by Al. (Skywave): Dec. 12, 2011.
member - Monday, December 12, 2011 at 06:18:14
The coil set and box that came with the R106 MK11 receiver. This set consists of nine general coverage coils, these coils do not have the bandspread facility.
The coils all have an ID plate with an air ministry type reference number on them, all coils have the same serial number on them, the box and its fittings they are in appear to be original except for the restraint chain attatched between the lid and the box. The original logging scale covers were suffering from the usual symptoms and have been replaced for the moment with thin clear plastic sheet.

Lawrence. 12/11/2011.