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Reviews Categories | Receivers: General Coverage | Racal RA6778C Help


Reviews Summary for Racal RA6778C
Racal RA6778C Reviews: 1 Average rating: 5.0/5 MSRP: $UNKNOWN
Description: Professional general coverage receiver. 10 KHz - 30 MHz, LSB/USB AM CW FSK, TEMPEST certified.
Product is in production.
More info: http://
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You can write your own review of the Racal RA6778C.

W9LBB Rating: 5/5 Oct 5, 2003 22:24 Send this review to a friend
A very interesting receiver indeed....  Time owned: 0 to 3 months
Here's a receiver that we're not likely to see too many of here in the United States. Even tho it was built here (at Racal's facility in Maryland), the main customer for it was the Defense Department. Between the insanity called the Electronic Communications Privacy Act (ECPA), whatever craziness the so-called "Patriot Act" comes up with in the future regarding communications gear, and the DoD's recent idiotic policies about "demilitarizing" any equipment more high tech than an anvil (usually, with a sledgehammer or a bulldozer tread liberally applied to the front panel) before surplussing it to the general public, this rig is destined be a very rare bird in US ham shacks.

That's a shame. In my recently begun love affair with "Premium" receivers (and Racals in particular), this one has to be the most interesting designs (from an engineering standpoint) I've run across so far.

BTW... before you ask, MY rig was imported from Canada, where it was apparently declared military surplus.

I fell in love HARD with the British built Racal RA1772! It's got to be one of my favorite receivers among the MANY that I've owned over the years. Despite it's truly excellent performance it's downfall was that it was designed for use by a HUMAN operator at the controls; is has no provisions for remote computerized control.

The RA6778C appears to be Racal USA's answer to that shortcoming, plus addressing some other specialized needs.

The RA6778 series is, essentially, a microprocessor controlled version of the older RA1772 design. Furthermore, as is pointed out in Fred Osterman's book, the RA6778 series is designed to conform to the Defense Department's TEMPEST standards.

One of the goals of the TEMPEST program is to reduce the electronic signature of the electronic gear used aboard military ships and aircraft... in line with the other goals of TEMPEST, essentially depriving potential enemies of electronic intelligence gathering opportunities caused by stray RF radiation from the equipment.

To achieve that goal, this rig is SHIELDED!!! Osterman claims that it is probably the most heavily shielded receiver ever produced. After looking over my version, I can believe that!

Besides the usual rigid, cast aluminum chassis that Racal is known for, there are individual sheet aluminum shields around circuit boards which are either exposed or placed in groups in shielded compartments in the RA1772. Cable connectors have sheet metal shielding hoods placed over them. The manual specifies ALL RF radiation from the rig (oscillators, digital circuitry noise, everything) to be less than 10 microvolts throughout the entire mesaured frequency range between 10 KHz and 1 GHz. When the top and bottom dust cover plates are on, this rig is buttoned up TIGHT!

Like the RA1772, this rig is double conversion, with IFs at 34 and 1.4 MHz. Unlike the 1772, there seems to be little or no variation of IF filter choices in a stock RA6778C (the RA1772 was downright promiscuous with the IF filter options available from the factory!). Standard filters (all beautifully made crystal lattice filters) seem to be for bandwidths of 8.0, 3.2, 1.25, .75, .4, .25, and .15 KHz. They're pretty emphatic about these choices; the available bandwidths are silkscreened on the plastic over the readout display panel... if you do a filter swap on this rig, you'd better think about the hassles involved in neatly relabeling that panel!

The rig can be tuned with either direct keypad entry of the frequency you want, or with a large, gorgeous cast aluminum main tuning dial (with fingertip spinner!) that moves the yellow LED readout display at user selectable rates of either SLOW (10 Hz per tuning step), or FAST (100 Hz per tuning step).

Unlike the RA1772, there are no mechanical rotary switch controls on the front panel; everything is done through two keypads (nice, long travel Hall Effect keyswitches). Most everything is pretty intuitive; there were only a couple of features that I needed to find about in the manual.

Speaking of those features... this dog can do a few tricks that it's parent rig can't.

The rig has 90 programmable memories (they save frequency, mode, filter choice, AGC setting). There is a SCAN function that allows you to step thru flagged memory channels at rates ranging from 100 MS to 10 seconds pause per channel.

BTW... According to Fred Osterman's book there are OTHER memory configurations and capacities in other versions of the RA6778... I'm strictly dealing with the C model in this review.

There is also a SWEEP function in the rig that I find unique.

To use it, simply take three contiguous memory channels. In the first (F1) program in the lower limit of your proposed sweep. In the second (F2) program in the upper limit of your sweep. In the third (F3), program in the size of the scanning step you want to use (minimum step size = 10 Hz).

To start scan, load F1 from memory by hitting RECALL while in either MEMORY VIEW or MEMORY ACTIVE mode, and then punch SWEEP. Dwell time of the sweep steps is controlled from the keypad in the same way as it is in memory channel scanning.

Two VERY unusual features in this rig...

There are apparently outboard boxes intended for use with this rig.

One is apparently an antenna selector matrix switch, possibly with a tunable RF preselector in it. With this unknown box, from the front panel you can select one of SIXTY FOUR antennas! The overhaul manual indicates that this box is controlled by a BCD signal coming from a rear panel connector.

There is also a connector there marked AUX. It took a bit of luck to discover what hooks up there...

Apparently, the AUX connector controls outboard VHF / UHF converters.

This was discovered by chance.

On top of the rig is a sticker that warns users to wipe the memories before shipping the radio (if that isn't a sure sign of a radio meant for use by SIGINT spooks, I don't know what is!). Well, someone screwed up, and forgot to wipe the memories before I got the rig.

I was surprised to find a NUMBER of frequencies programmed in that are in the 30 - 75 MHz range! Just for grins, I tried to manually program in a couple of frequencies that are also beyond the radio's basic tuning range; the microprocessor flatly refused to let me do so. It obviously KNOWS when the VHF / UHF converters are connected to the rig.

Oddly, when I loaded one of these spook VHF frequencies to be listened to, the ones below about 33 MHz WOULD load (those above that frequency gave a FAULT indication on the panel indicator). A signal generator tuned to the spook frequency WAS indeed heard, but not all that well; sensitivity was off somewhat. Moving the main tuning dial with one of these oddball frequencies loaded results in the radio instantly reverting to 0.0 KHz.

Performancewise, this receiver is a dream... all that extra shielding and filtering makes it a VERY quiet receiver indeed.

It retains the rock solid stability of it's RA1772 forebearer, and it also shows a feature from the later RA6790/GM; the BFO is derived from the synthesizer, and tune in 10 Hz steps!

This is one SERIOUS receiver! I like it... a LOT.

If you are interested in more information or possibly buying one of these critters, check out the web page of Surplus Sales of Canada.

BTW... I apologize to Ron at Surplus Sales; the photo I used at the top of this review was purloined from his web site. I hope he'll forgive me for that. I've done some business with him recently; Ron is a good guy to deal with.


73's,

Tom, W9LBB
 


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