Inside Those BIRD Slugs

Return-Path: Received: from rly-da06.mx.aol.com (rly-da06.mail.aol.com [172.19.129.80]) by air-da05.mail.aol.com (v121.5) with ESMTP id MAILINDA052-a714825ee323c4; Sat, 10 May 2008 14:50:02 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-da06.mx.aol.com (v121.5) with ESMTP id MAILRELAYINDA061-a714825ee323c4; Sat, 10 May 2008 14:49:35 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Juu8C-0000bw-Tw for rs_out_1@blacksheep.org; Sat, 10 May 2008 19:49:16 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Juu8C-0000bn-3j for rsgb_lf_group@blacksheep.org; Sat, 10 May 2008 19:49:16 +0100 Received: from smtp805.mail.ird.yahoo.com ([217.146.188.65]) by relay3.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1Juu87-0003xO-U6 for rsgb_lf_group@blacksheep.org; Sat, 10 May 2008 19:49:16 +0100 Received: (qmail 51951 invoked from network); 10 May 2008 18:49:06 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=btinternet.com; h=Received:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=Kuhb9YxM4enCLGWyJVh2OF4x88xSrJS53/2TuTFOHRUFoNa2A3EIFeK8cDvxpc0jzWvjcGjScrO4FPk7brGvUvskQwVKyyx8JYKN2SrwCLH8cb3CP17VM2FBHmiXDeqvjq9Fv+R0oI8xrAnJJ+csLWdOrhFB1ORCiXhCaw0IT10= ; Received: from unknown (HELO oemcomputer) (robertgjbennett@btinternet.com@86.142.22.55 with login) by smtp805.mail.ird.yahoo.com with SMTP; 10 May 2008 18:49:01 -0000 X-YMail-OSG: 4OB3ITcVM1njgj.9GSqvJpF6oaIOOgcA2yf0vL1DWTYQUe6mYFhXnN_HfZO8m_5KxJZRHR.arxrC6b8ZxoTAxO8UyscejAOee8oNFAGXTY363vYZjNTnWN_1Ocdt.Lw- X-Yahoo-Newman-Property: ymail-3 Message-ID: <000b01c8b2ce$c20b80c0$4001a8c0@home> From: "Robert Bennett" To: References: <001001c8b2b5$bc4592c0$0e00000a@AGB> Date: Sat, 10 May 2008 19:50:45 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 DomainKey-Status: good (testing) X-Spam-Score: 0.9 (/) X-Spam-Report: autolearn=disabled,HTML_COMMENT_SAVED_URL=0.647,HTML_MESSAGE=0.001,HTML_SHOUTING5=0.169,HTML_TAG_EXIST_TBODY=0.126 Subject: LF: Re: Peak reading cct for Bird 42 Content-Type: multipart/mixed; boundary="----=_NextPart_000_0008_01C8B2D7.22CAFBE0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: *** X-Spam-Status: No, hits=3.5 required=5.0 tests=CASHCASHCASH,CLICK_BELOW, HTML_20_30,HTML_COMMENT_SAVED_URL,HTML_FONTCOLOR_BLUE, HTML_FONTCOLOR_RED,HTML_LINK_CLICK_HERE,HTML_MESSAGE,HTML_SHOUTING5, HTML_TAG_EXISTS_TBODY autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-AOL-IP: 193.82.116.20 X-AOL-SCOLL-AUTHENTICATION: listenair ; SPF_helo : n X-AOL-SCOLL-AUTHENTICATION: listenair ; SPF_822_from : n ------=_NextPart_000_0008_01C8B2D7.22CAFBE0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit This link any help? Robert ------=_NextPart_000_0008_01C8B2D7.22CAFBE0 Content-Type: text/html; name="Inside Those BIRD Slugs.htm" Content-Transfer-Encoding: quoted-printable Content-Disposition: attachment; filename="Inside Those BIRD Slugs.htm" =EF=BB=BF Inside Those BIRD Slugs

Inside Those Bird=20 Slugs

Did you ever end up with or do you now have a de= ad=20 Bird slug? No, not the kind you have in your shotgun but t= he=20 kind which fits inside the Bird Wattmeter series which makes the= m so=20 valuable. Have you ever wondered what was inside them?&nbs= p;=20 Well, I had one which I purchased at a hamfest ("Is it wor= king=20 OK?" "Sure, it is. I used it right before I headed=20=
down here to the hamfest.") &= nbsp;=20 I foolishly believed the seller but once I tested it at home, I=20 realized that I had a dead slug. I have since found a way=20= to=20 test them before paying the money and I'll be glad to share that= =20 info later.

In addition, I was always curious as to what was on the insides of=20 those little beasts. After all, what could be inside to make th= at=20 little thing worth so much money? Since mine was dead, and I had= =20 little to lose, I opened it up to see. I will share with you the= =20 inside story, and I now know why they are so dear to the pocketbook. =

I did not take this project lightly. I spe= nt=20 long hours searching the Internet but was never able to find any= =20 information on the slugs themselves, either pictures or text, to= =20 describe what the folks in Cleveland placed inside those little=20= gold=20 cylinders. I hope this article can save someone else some=20 search time if they attempt the same endeavor.

First, to test a Bird slug (assuming that you are going to a hamfes= t),=20 take along a small VOM that has, at least, a resistance scale. I= f=20 the seller (assuming you are also buying at a hamfest) will allow you=20= to=20 test it, place the VOM on a higher resistance scale (I used the 20K sc= ale=20 on the little yellow $9 marvel I had). Hold the slug in one hand= and=20 place one probe on the round shell of the slug while carefully touchin= g=20 one of the small connection which is exposed on one side. Then=20 reverse the VOM leads. Test it just like you would test a diode=20= --=20 you want continuity in one direction and an open connection the other=20 way. Then test the connection on the other side of the slu= g=20 the same way, expecting the same results. If you find=20 continuity, or a very low resistance, from the shell to a connection i= n=20 both directions, something is shorted in the slug. If you find n= o=20 continuity in either direction, something is open in the slug. =20 Either way will cause it not to work. On the one I had, I had n= o=20 continuity.

Over a period of months I would pick that slug up and try to twist,= =20 poke, pull and generally try to see how to get inside it to see if=20 anything was obviously gone. It resisted my every=20 attempt. My wife would have said, "throw it away... it isn't any= =20 good. Just forget the money that you wasted on it..........It's=20 gone!"

I don't think so. 'Course I really didn't tell her that I bou= ght=20 a dud so she didn't actually say that. Finally, over a yea= r=20 past the original purchase, I decided to take drastic steps. Aft= er=20 all, it's dead anyway ---- what can I hurt?

With my Dremel tool and several different bits and stones, I was ab= le=20 to grind down past the aluminum disk which is the label, and pop the l= abel=20 disk off. I regret that when this activity took place, I did not= own=20 a digital camera so I have no actual pictures of the following=20 steps. Even though I now have a camera, I cannot bring myself to= =20 re-enter the slug, just to get pictures. I will attempt to be, i= n=20 words, as descriptive as a camera would have been in pictures.

Once the label disk was off, it revealed a cavity in the center wit= h a=20 single screw which was covered with a sealer to show whether it had be= en=20 "messed with." Again, nothing to lose so I unscrewed that screw= =20 which released the larger circular part of the slug. This is the= =20 widest part of the slug which has the grooves and is gripped to=20 rotate the slug in the wattmeter housing.

Once the finger piece was off, I could see a 1/2 watt resistor with= a=20 piece of spaghetti over one lead. It was soldered on one side t= o a=20 small terminal which was one of the two connection pieces which are al= ways=20 visible on the side. The other lead of the resistor connec= ted=20 to another terminal and on to the top of a diode coming through the=20 remaining part of the slug.

Two more screws were also revealed and once they were removed, the=20 white nylon cover which shielded the primary RF detection pieces was=20 removable. This round white piece of nylon is the piece which yo= u=20 see on the lower section of all Bird slugs. The slug I had was a= 50C=20 which was calibrated for 50 watts in the range of 100-250 MHz.

The RF detection parts were a 1 1/2 turn coil of about #18 silver=20 plated wire connected to the diode on one end and a flat feed-thru=20 capacitor on the other. The white nylon cover was actually a=20 machined-out piece with room to go around the coil and feed-thru. &nbs= p; I=20 had originally thought it to be just an inverted bowl-type cover but i= t is=20 much more rugged than that.

I did not bother the coil or other parts inside the slug once I=20 realized that my problem was an open resistor. This resistor was= =20 marked 14K 1% and had, no doubt, gotten too hot from excessive power s= o it=20 opened up. As Fortune had smiled upon me, I had an exact replace= ment=20 resistor which helped to speed the repair. I carefully ben= t=20 the leads on the replacement resistor to look exactly like the one it=20= was=20 replacing. The defective resistor was easily and quickly removed= and=20 the replacement fit back perfectly. I tried to use the least amo= unt=20 of heat on the connections so as not to risk changing the value of the= =20 resistor.

Putting things back together, everything fit fine and there were no= =20 left-over pieces (unlike some of my previous projects). The slug= was=20 tried and worked as it was supposed to. At least, it read upscal= e=20 when power was applied through the wattmeter connectors.

Bird slugs are expensive because they are manufactured to close=20 tolerances and I imagine it takes quite a bit of time (Time =3D $$$$)=20= to=20 assure the accuracy to which users have come to expect of Bird=20 products. My repaired slug certainly did read something but ther= e=20 was no assurance that it would anywhere near the accuracy that was=20 demanded of that unit. I compared the repaired slug to another I= had=20 which covered the same range and they read to same values. Y= es,=20 since that one had been defective and I still needed that value, I had= =20 purchased another. The repaired slug read the same as the=20 untouched, other one which had become its replacement. Lucky? &n= bsp;=20 Probably. Happy? Absolutely!!

Had I been able to verify the contents and inner make-up of the Bir= d=20 slug earlier, that is, if I could have read what you just read, I woul= d=20 have started the repairs much sooner. It may be that I was just= =20 lucky and attempting this project again on a different dud slug would=20= have=20 resulted in a much different outcome. I was, however, very pleas= ed=20 with the final result on this particular attempt. If you attempt= the=20 same, I hope you have similar success because, as we all know, "A Bird= in=20 the hand is............ oh, never mind....."=20 &nbs= p; =20 ----- K5LAD

Cl= ick=20 here to go to More Info on Bird Slugs

Cl= ick=20 here to go to Even More Info on Bird Slugs

Cl= ick=20 here to for Additional Info on Modifying Bird Slugs

Cl= ick=20 here to for Even More Info on Modifying Bird Slugs

Updated 11/13/06=20 11:36 AM<= /P>

Note: Slug p= ictures=20 were borrowed from several peoples' ebay sale items. =20 Thanks!

13122 hits since August 6, 2002 3D"arrowblu_top.gif Cli= ck to=20 return to Home Page

=20

Carefully examining the dead slug revealed that=20 someone had used some type of grinding tool on the face of the s= lug=20 on two sides. (I know, I know, I should have seen that=20 sooner......and especially before I bought it.....) The tw= o=20 round grinding spots were within the arrow which seems to be on=20= all=20 Bird slugs showing which direction it is to be turned. &nb= sp;=20 One was directly within the arrow head and the other at the=20 opposite, tail side of the arrow.

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