On 26/02/2010 07:40, Michael Buckley wrote:

There was talk on one of the groups, about these (Sorry I forget which)

Personally I see no problem with charging Clansman Batteries with the
"official" chargers - DCCU, ACCU and IBMS.
YThey are all quite chehap on the local surplus market

However I have just come across an adveert which might interest some - I
have no idea of cost or if they will sell direct, but they are based in
Newbury, UK

Have a look at PSCH15 Series N1MH/NcCD chargers
www.powersolve.co.uk

Mike B
m1ccf

g6lxk wrote:

Hi,
I have a Racal Communications Drive Amp sub-assembly unit, circa 1981, which seems to be HF broadband, 12-28v DC voltage, Racal Comms part number CA607399. I cannot find any data about it anywhere. I have fed in about 4W at 80m (3.7MHz) and get about 50W output. As it has a pair of BLW95s in the final, I am not sure that it is running at its full potential. Can anybody help me with some information, or perhaps suggest the product that it was used in. I have a photograph of the PCB, which I can you send if necessary.

Many thanks,
Howard, G6LXK

Drive amp CA 607399, pcb code ST607230

Howard, I don't know that particular number, but most of those are 28 Volt, and Class A, designed for driver service in one of the 1/2 to 1 kW transmitters that Racal made. Usually designed for 100 to 200 mW input as well if they are multistage, so 4 Watts in may be a bit much :^) You may find some circuit details if you search on line for the transmitters, TA1818 or TA1823 is the best I can do from memory.

Also as they were designed to be air cooled with a blower they may get hot without one.

Dan

ac6ao / g3ncr

开云体育

Hi Scott,
Check out this item, 190375189093 presently on ebay.

The seller states that it has the proper 6-pin connector for the syncal 30 radio.

Regards

Wal, G4CGF

To add a bit more info, you need a handset with a "Larkspur" type connector. The standard telephone handset used with those radios is the Racal Part number ST719215. The Amphenol connector type used has a normal 'N' keyway orientation, whereas the Clansman ones have the 'F' keyway orientation.

Peter

开云体育

Hi,
I have a Racal Communications Drive Amp sub-assembly unit, circa 1981, which seems to be HF broadband, 12-28v DC voltage, Racal Comms part number CA607399. I cannot find any data about it anywhere. I have fed in about 4W at 80m (3.7MHz) and get about 50W output. As it has a pair of BLW95s in the final, I am not sure that it is running at its full potential. Can anybody help me with some information, or perhaps suggest the product that it was used in. I have a photograph of the PCB, which I can you send if necessary.

Many thanks,
Howard, G6LXK

Drive amp CA 607399, pcb code ST607230

I have a PRM4090 and a Syncal-30, both missing handsets. They take a
standard 7-pin or 6-pin military M-S connector, as found in US military
stores (or from Amphenol). However, if I put a PRC-25 handset on them,
I get very low modulation, making me think the handset output is not
correct.

When I talked about this year before, I got numerous replies telling me
to buy handsets on Ebay, that they were all over. Well, none of them are
in the US... and after a year of looking I bit the bullet and spent way
too much shipping for a handset marked 5965-99-620-5669 which claims to
be for the Clansman sets. It has a connector that looks identical except
for one guide mark in a different place.

So.... anyone in the US care to trade for a handset that will actually
work with the Syncal-30? Or is this the right general handset with the
wrong connector?
--scott

An HF antenna woven into a tabard was used in the early 70s as part of an experimental underground comms system. The surface antenna was a multiturn loop laid on the ground. I believe this was at about 3MHz.

Also, I have a 100w Pye mobile VHF transceiver that was used by the security services in conjunction with a slot antenna cut into the roof of a vinyl roofed car (remember them?) the install was completely invisible but I feel sorry for anyone sitting inside who had braces on their teeth!!!

Other variations on the stealth/low profile theme have been around for years. Pye used the carrying strap for the Bantam and the PF70 as an antenna for their low band models and rear windscreen heaters have often been used as antennae for both broadcast reception and VHF/UHF comms.

Phil

I'm surprised at the "at last??" part. Its been going on for years. For example, try a Google for "Comwin antenna". The Comwin antenna project was over 10 years ago and looked at putting HF, VHF, and UHF antennas onto a soldier, but tailored into the soldiers clothing and helmet. Most of the technical reports are no longer freely available on the web, but its an area I was researching myself a few years ago. You can still find brief Comwin reports/presentations via Google.

Low profile vehicle antennas are another area that's seen a lot of research, but the laws of physics will only allow you to do so much if you want high performance (as the users usually do) as well.

With the USA concentrating on their JTRS radio systems there has been a developing need for these sorts of antennas (smart and low profile) over the past several years, and I know that a lot of research has already been done in many countries. Unfortunately, its not an area that I work in any more.

Cheers,

Peter

Army Researchers Focus on Smart,
Stealthy Antennas at last??

February 16, 2010 - by Henry S. Kenyon

If U.S. Army scientists have their way, future antennas for vehicles and dismounted infantry will be smaller and more nondescript and will
feature greatly increased reception. Research is focusing on lightweight conformal antennas that can be built into soldiers uniforms and
equipment as well as vehicle structures.
One of the major thrusts of the Armys work is making antennas less obvious, says Dr. Steven Weiss, team leader of the U.S. Army
Research Laboratorys (ARLs) antenna team. He notes that Army researchers also are examining new technologies such as
metamaterialsengineered substances that do not have properties found in nature. For example, mounting antennas to conform to the
side or the inside of a vehicle can affect their performance, but antennas made of metamaterials may counteract some of these effects.
The Army is interested in developing conformal antennas for ground vehicles. These could be used for communications or jamming
improvised explosive devices. Because they are part of the vehicles structure, they lower its overall visual profile, making it more
survivable on the battlefield. Antennas could be inconspicuously mounted onto vehicles in a number of ways: flush against the vehicles
skin, incorporated into part of its structure such as a bumper, or conformed to the contours of the vehicles shape.
But developing conformal antennas for ground vehicles presents a variety of challenges. These issues include ground effects, such as radio
interference, and size and weight issues for vehicles equipped with the antennas.
Weiss notes that researchers want to develop electronically scannable antennas that do not move physically but would enable radios to
maintain point-to-point communications. Electronically scanned phased antennas are used for radar systems on ships and aircraft, but
their cost prohibits mass installation on ground vehicles, he says.
The Army has a pressing need for antennas that provide data and satellite communications on the move. Weiss cites the ARLs satellite
communications on-the-move effort as an example of the services research goals and challenges. How do you replace a double
gimbaled dish antenna with a phased array that is not a budget buster or requires a refrigeration system to keep the antenna cool? he
asks. Another criteria is the ability to support enough bandwidth to manage multiple communications functions.
In addition, ARL scientists are examining metamaterials for new antenna applications. Weiss cautions that there was a great deal of hype
about metamaterials when their potential was first developed but adds that they can be effective for work on conformal vehicle antennas.
He notes that researchers are interested in one particular type of application known as artificial magnetic conductors (AMCs

--- In Racal-manpacks@..., david ludlow <bearsnack009@...> wrote:

??Hi Martin
Im Dave= kg4lqt
?? I ??wanted to ask you if you knew of a place to get some final transistors for a racal 921.. im using some finals that work but are alittle underpowered. Im also interested in an inexpensive amp.?? Do you know of a good tfor racal radios?
thank you??
i appreciatte any help or information you can offer
dave KG4LQT
??

_________________________________________________

hi I am 4z4rb Baruch
The finals are hard to get very much unobtainium's
2N5070 as stud units and the smaller ones are 2N5026 SAME CASE AND VERY RARE.
I made my own amp for the syncal with MRF138 works much better! later I added 2xMRF150 to get close to 3ooW out on 50v at 28V I get close to 170W with alot of headroom!
4z4rb@...

Hi there does anyone have the manual for the pv-1313 and 1311 and or the drawings for the control cable

email g7jwr@...

Martin G7JWR

Hi all

I have asked this question ages back, without success but will ask again in case anyone has come across any info more recently.

I am looking for schematics for the Racal PRC-139 radio, or any of it's variants, the PRC-6725, the PRC-4725 etc.
I have a couple of them that are off frequency and cannot see any way to adjust the reference frequency.
They all use the same RF board (30-88mhz) so any schematic would probably do the job.

regards
Tony

Hi!

Are you sure its not an A40/A41 gooseneck?

Look more like it to me, though it will probably fit!

Mike

The item on ebay is the centre section of the second pattern battle antenna
issued for the British A41/A42. They were also used on the A40.
Above it is fitted a simple 4-section rod antenna with an elastic nylon
inner cord.
Below it, i.e. connected to the set, is fitted an adaptor that accepts the
flexible section as a push-in fit, and connects to the A41 short antenna
socket by a bayonet style fitting. This adaptor has a distinctive red
locking ring device to tighten it on the set and secure it against loss.
These three items replaced the original all-in-one antenna which suffered a
high level of breakages and was expensive. Unfortunately they were more
prone to falling apart during moments of stress due to the parts only being
held together by spring clips.

The long antenna socket on an A41 is indeed threaded (3/8in x 24 UNF) but so
is the short antenna socket if you look closely, although British issue
antennas didn't use the screw thread, which was provided to give commonality
with the antennas used with the American AN/PRC 10 series sets.

Andy G8JAC


..>Sorry,
..>
..>Meant to say the A41 base for the long antenna is threaded.
..>
..>Tom
..>
..>
..>> Hi Dave,
..>>
..>> I think you are correct. It is a Racal base for the TRA921/931/906 etc.
..>> It works just fine for HF. The A40/41 base is threaded so it is not
..>> correct for that radio.
..>>
..>> Tom Bryan
..>> N3AJA
..>>
..>>>
..>>> I came across this item on Ebay that may be of some interest. It looks
..>>> like a flexible antenna goose neck as used on TRA921/931 etc.
..>>>
..>>> 220408131799
..>>>
..>>>
..>>> Dave g1jwg
..>

Tom B wrote:

Hi Dave,

I think you are correct. It is a Racal base for the TRA921/931/906 etc. It works just fine for HF. The A40/41 base is threaded so it is not
correct for that radio.

Tom Bryan
N3AJA

I'd second that Tom, the dimensions given seem to match mine. The goose neck for the TRA967 is similar however but has a smaller diameter piece to go into the fitting on the radio. I don't have this one though.

Dan
ac6ao / g3ncr

Sorry,

Meant to say the A41 base for the long antenna is threaded.

Tom