This microphone plug 3/16" or .206" is also used with Collins gear and avionics microphones.

Switchcraft makes them.  Many distributors sell them, including Newark Electronics.  They are avaialble every week on eBay at reasonable prices.  

Surplus Sales of Nebraska sells genuine Collins tagged PJ-608 (expensive tag).
http://www.surplussales.com/Collins/CollMisc-1.html

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THis lamps can also be found at many hobby stores that carry model railroad parts and accessories.

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Jackson Brothers was founded in 1923 to manufacture variable capacitors and accessories such as tuning drives and dials. Today, distribution and production facilities are owned by the Mainline Electronics Group.
http://www.mainlinegroup.co.uk/jacksonbrothers/

For orders:
Mainline Electronics
Unit 1A Cutters Close
Coventry Road
Narborough
Leicester LE19 2FZ
UK
Tel: (+44) 116 286 5373
Fax: (+44) 116 286 7797
Email: anona@mainlinegroup.co.uk

Another option is Oren Elliott Products (OEP)
http://orenelliottproducts.com/index.html

OEP was the original supplier for many Heath capacitors and planetary drives.

Oren Elliott Products, Inc. is the largest US domestic manufacturer of air-dielectric variable capacitors.
Producing capacitors since 1925, the OEP Plant I was first known as American Steel Packaging Company and then as All Star Products. In those early years, their applications and major products were almost exclusively focused on the broadcast and short-wave radio industry (which was a huge market in late 1920s and 1930s).
During World War II, ASP supplied the Allies with 3500 capacitors per day, and by the end of the war the company was the world's largest producer of air trimmers.  In 1983, Oren Elliott Products Inc.'s was created and expanded into new facilities (Plant II) to include CNC lathes, CNC vertical machining centers, CNC and conventional Swiss screw machines, and all of the support equipment necessary to enable OEP not only to produce all of the machined subcomponents for their capacitors.

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SINDK8 -

You may be lucky and have only lost some discrete components on the input side of this amplifier, BUT unless you are have good soldering skills and sufficent knowledge to test the trasnsistors with a VOM -- you could easily waste time ($$/hour your labor) and spend $$ for parts that you really would not need to replace.

IF this is an educational project, then I would highly suggest a bit of reading [Motorola Application Notes - authored by Helge Granberg(sk)].  These are available at the CCI web site.  Application notes AN791 is close to this design - CCI kit number 875

RF Parts will have these transistors and alost every compnent that you woudl need.  THey also have some of the Motorola application notes on file.

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So, you just need to decide which interface (Yaesu, Ameritron, AmpKeyer, homebuilt) that you want.

Ameritron tells you this on their web site (about their amplifiers - including the AL-811)

Why you need the ARB-704?

Amplifiers can damage radios if the amplifier has too much relay control voltage, voltage spikes, or excessive current on the relay control line. Such damage often appears as "stuck" or "sticky" transmit relays in exciters or shorted transistors on transmit control lines. In most cases where the radio is damaged, the system transmits normally but the external amplifier stays locked in a "transmit" mode. This prevents receive signals from coming through the amplifier with normal levels whenever the amplifier is in the "ON" or "OPERATE" position.

The ARB-704 has many electrical advantages over conventional relay buffer systems. The ARB-704 has no moving parts, switches almost instantaneously. It is noiseless, has very long life, and will not develop dirty contacts. It operates with negative, AC, or positive amplifier relay control lines.

It works with any relay voltage (AC, positive or negative) up to 200 peak volts and any relay current up to 300 mA. The ARB-704 is fully compatible with conventional amplifier relay systems. It is especially suited for buffering vacuum relay QSK amplifiers, since the ARB-704 does not affect attack or release times in a deleterious manner.

The ARB-704 operates with transmitters or transceivers that pull amplifier control lines to ground, or output a wide range of positive or negative control voltages. The transmitter only switches currents under .35 milliamperes and very low voltages when using the ARB-704. Measures a super compact 4-1/4W x 1-3/4H x 2-1/4D inches

The ARB-704 is supplied with the following:
1. One power connector cord and plug with red wire (+12 Volts) and black wire (- and ground).
2. Three phono (RCA) cord with connectors on each end. These cables are for relay, ALC and amplifier control lines

The Yaesu accessory that you need for your Ameritron AL-811 amplifier keying is the Yaesu FRB-757 (that should be listed in your Yaesu manual)

The Ameritron part is an Amplifier Interface Buffer - ARB-704:
http://www.ameritron.com/ameritron/products.php?prodid=ARB-704

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Here is a plug-and-play solution for you
http://www.theheathkitshop.com/ampkeyer.html

Yaesu did make an external relay box for your FT-757GXII ... when used with amplifiers - like the AL-811 .. used ones appear on eBay.

Ameritron will have an external unit -- if you do not have building skills.

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Here is a good design, by Virgil Stamps K5OOR
http://www.hfprojects.com/projects.htm

Drive requirement: 1-2 watts RF (internal 3dB pad)
Power Output: 35 watts RF output (nominal) 160-10 meters; gain of approximately 15 dB
Spurious products: -40dB or better @ 35 watts
Harmonic content -45dB or better @ 35 watts
Filter Selection: manual 6-position rotary switch; 160, 80, 40, 30-20, 17-15, 12-10 meters.

A six-position Low-Pass Filter Module. The function of the module to attenuate harmonics from the transmitter to be below 40dbC on all HF bands, 160-10 meters. All of the parts including the rotary switch are mounted on a small circuit board.
Notice the number of torroids for filtering each band !

gb

I have heard they are made in Italy and someone bought a boatload -- look on eBay they have been there for a number of months.

Just like that great diet pill, did you lose weight?

I would scrap for raw parts -- you may get your money back that way.

gb

Ken -

First, there are a large number of amplifiers on eBay and at hamfests that have fallen into disrepair or abused (amatuer estates, ignorant operators, illegal CB or "freeband" usage, etc.).  This creates a ready supply of candidates for repair, restoration or raw parts (cabinet) -- I find that this can be quite rewarding -- and many of these are purchased for less than parts value.

Second, you need to decide whether you deisre a tube (glass or ceramic) or solid-state (bipolar transistor or FET) amplifier.  The differneces can be important to your fabrication skills and operation / usage.

Heat is handled in 2 completely different approaches.
Power supply (Voltage and current) designs are quite different in requriements and construction.

For new construction, and if you desire a tube design -- I would focus on ceramic based tubes.
http://wd7s.home.att.net/contents.htm

The G3SEK control boards are outstanding for tube amplifiers
http://www.tomstubes.com/kits.htm
 
There are a number of inexpensive surplus Russian ceramic tubes on the market.  Lawson Summerrow W4EMF has been performing a number of converisons:
http://www.nd2x.net/W4EMF.html

http://www.nd2x.net/WB8WJU.html#MLA2500

For slid-state deisgns - I would focus of Helge Granberg's work (Motorola Application Notes).  CCI kits that follow the Motorola Notes
http://www.communication-concepts.com/default.htm

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Matt -

No flames, but trademark / name registration law is very specific -- and even more so after so well documented 1990s lawsuits involving usage of Intenret DNS names (e.g., xx.com; xx.org, etc.).

The information posted is from the Palomar Engineers web site .. and they are a registered owner of the Palomar name.

gb

RF Parts has all of the Svetlana information (pictures of difference of 572B tubes, neutralization changes - when required, etc.) on using these tubes in Yaesu 2100 series amplifiers.

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Ty -

Please pass on this inforamtion concerning "Palomar" amplifiers - educational for all concerned.

eBay has been flooded with "new" Palomar amplifiers.

Palomar has been out of business for 25 years - so older amplifiers (transistors used will reveal true age) are genuine - but NEw, not possible.

No address has ever been provided by the maker of these "new" amplifiers (likely a foreign import using the Palomar trademark name).
==========================================
Palomar is a REGSITERED TRADEMARK of Palomar Engineers, Inc. It is the Spanish word for “dove cote”.  (La Paloma = The Dove). The mourning dove is a common bird in Southern California. A major feature of San Diego county is 6000 ft. Palomar Mountain.

Local California Institutions using the name (and permitted - under law):

Palomar Observatory. On Palomar Mountain, with the 200 inch Hale telescope. Managed by California Institute of Technology.
 
Palomar Hospital. Escondido’s medical center.
 
Palomar College. A community college in San Marcos, Calif.
 
Palomar Airport. Airport code CLD. Carlsbad, California
===========================================
Businesses legally using the Palomar name include:
 
Palomar Engineers, Inc. At this Web site.
http://www.palomar-engineers.com/Palomar/palomar.html

Palomar Software, Inc. A Macintosh software developer in Oceanside, California.

Palomar Medical Technologies, Inc.  A medical equipment company in Burlington, Massachusetts.
 
Palomar Products,Inc. A manufacturer of audio, video, and data distribution systems in Rancho Santa Margarita, Calif.
 
Palomar Technologies, Inc. A manufacturer of automated assembly equipment in Vista, California.

Palomar Display Products, Inc. A manufacturer of commercial and military displays in Carlsbad, California
=============================
Extinct businesses (OUT OF BUSINESS) that formerly used the Palomar name:
 
Palomar Electronics Corp.  A manufacturer of CB linear amplifiers in the 1960’s and 1970’s.
WENT OUT OF BUSINESS ABOUT 1980. No trasnfer of name or assets recorded.  This business had NO conection whatever to Palomar Engineers, Inc. (trademark owner)

Palomar Telecom. A manufacturer of repeater controllers in the 1980’s. Went out of business about 1990.
=============================

gb

James -

Alpha should answer your inquiry within 24 hours.
http://www.alpha-amps.com/

I am restoring an Alpha 76A [K9EWJ(sk) previous owner was Elmer] .. and needed the new front panel (replace the sticky front panel) .. they were out of stock, but Anthony (Alpha customer service) took my name and right on scheudle he called me back 4 weeks later for payment information. "This is the customer service that I remember from ETO/Alpha"

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Edward -

If you use your VOM and measure the voltage where the bulb is at, you can then determine the bulb's voltage.  An LED could be used with a suitable dropping resistor (lots of colors as well as high brightness versions)

Here is a great LED tutorial page (Kelsey Park School - UK)
http://www.kpsec.freeuk.com/components/led.htm

Greg
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