20070817.ba v04_n079.bam.20070817 >From ???@??? Fri Aug 17 16:12:35 2007 -0500 Date: Fri, 17 Aug 2007 16:11:30 CDT From: Old Tube Radios To: Old Tube Radios Subject: BOATANCHORS digest 4079 Message-Id: <20070817211131.915BC3180FB@srvr1.theporch.com> BOATANCHORS Digest 4079 Topics covered in this issue include: 1) Re: 6HS6 sub by wb3fau@att.net 2) Re: 6HS6 sub by Garey Barrell 3) RE: 6HS6 sub by "Bill Hawkins" 4) Re: 6HS6 sub by WA5CAB@cs.com 5) Re: Boatanchors list - happy 15th birthday by "Kevin Anderson" 6) Re: Boatanchors list - happy 15th birthday by spr@earthlink.net 7) BAs -15th! by wb3fau@att.net 8) Congratulations On Fifteen Years!! by "Liles Garcia" 9) Re: BAs -15th! by "Arden Allen" 10) Re: BAs -15th! by Steve Berg 11) Re: BAs -15th! by "Al Parker" 12) RAO-7/9 receiver info? by "Art Lebermann" 13) Re: RAO-7/9 receiver info? by WA5CAB@cs.com 14) Re: RAO-7/9 receiver info? by "Art Lebermann" 15) Re: RAO-7/9 receiver info? by "Tom Rauch" 16) Re: RAO-7/9 receiver info? by Al Klase 17) Re RAO-7/9 by "PHIL" 18) Vintage/Rare? Morrow Radio MFG CO VHF Low Band Portable! by "TChirhart" ---------------------------------------------------------------------- From: wb3fau@att.net To: Old Tube Radios Cc: "Arden Allen" Subject: Re: 6HS6 sub Date: Wed, 15 Aug 2007 17:44:55 +0000 Message-Id: <081520071744.3307.46C33B970002B39200000CEB21604666489A0E00CC0D99@att.net> Not directly related- It is funny how that tube business worked out. They used color TV sweep tubes for outputs in these rigs, because they were plentyful and less expensive than the 6146s at that time. Now, the 6146s are cheaper. Russ. ------------------------------ Message-ID: <46C34C10.50800@mindspring.com> Date: Wed, 15 Aug 2007 14:55:12 -0400 From: Garey Barrell MIME-Version: 1.0 To: Old Tube Radios Subject: Re: 6HS6 sub Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Actually 6146's are not really cheaper any more. Aside from hamfest "bargains", most tube sellers are asking between $20-25, which is about the same as the 6JB6, when you can find them. The 6JB6 was chosen originally for their ability to produce higher power at lower plate voltages, as well as selling for about 60% of the price of a 6146 at the time. A pair will run 250W input at 650 VDC on the plates, while 6146s only hit about 170W at 750 VDC. Sylvania characterized and published Class AB1 ratings up to 30 MHz for their sweep tubes. Ham radio was in a "horsepower race" at the time, and that extra power with lower plate voltages was pretty attractive. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B & C-Line Service Supplement CDs wb3fau@att.net wrote: > Not directly related- It is funny how that tube business worked out. They used color TV > sweep tubes for outputs in these rigs, because they were plentyful and less expensive than > the 6146s at that time. Now, the 6146s are cheaper. Russ. > > > > ------------------------------ From: "Bill Hawkins" To: Old Tube Radios Subject: RE: 6HS6 sub Date: Wed, 15 Aug 2007 22:09:15 -0500 Message-ID: <004101c7dfb2$d3ee48d0$021ba8c0@cyrus> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Well, I got a BSME from MIT in 1960. Would have been EE, but they tore out the rotating machinery and replaced it with a course in vectors. So it goes. The business school folks looked down on engineers as tools of the ruling class. Didn't matter to me, as long as there was enough of Other People's Money to let me build what I thought was necessary. Sadly, that went away in the 70s with the oil crisis (manufactured with non-engineering tactics). A letter to the editor in the Minneapolis Star-Tribune (about the bridge) asserted that no engineer would skimp on safety factors. I replied that things had changed, but it wasn't published. Fact is, bridge design is done to a list of criteria. If the bridge stands for 10 years, then the engineering was just fine. After that, it becomes a maintenance problem, complicated by the tripling of the population. [The greatest threat to the quality of life is the quantity of life. Black holes for wealth are second.] Today, the budget rules, as management became very reluctant to add any "improvements." Now politicians use tax money to aid people who will fund their campaigns. Infrastructure falls to the bottom, as failure won't happen in their term. New stadiums bring in money, repairing bridges doesn't. So engineering isn't what it was in Victorian times, the age of brass and steel. A Victorian machine exudes the pride of the engineers. Today's designs are crippled by managers that are measured only by costs. That is why I lose myself in 40 year old designs, like HP and Tek, and why I remain a member of this list. Bill Hawkins P.S. How could I have forgotten Bobby Barmore as a contributor to this list! Her knowledge of old things was so great that I thought she was an old lady. Then a business trip allowed me to meet her at the TV station, and things changed. She is a delightful and sharp person, who has received as much bad luck as a person can have and still survive. She doesn't deserve it. So it goes. -----Original Message----- From: owner-boatanchors@theporch.com [mailto:owner-boatanchors@theporch.com] On Behalf Of Arden Allen Sent: Wednesday, August 15, 2007 12:24 PM To: Old Tube Radios Subject: Re: 6HS6 sub > ....Engineering decisions are made for all sorts of reasons. The point is, they're our decisions to make. Others get to second guess....... No disrespect intended, Dennis, but I worked for engineers for 25+ years and I know how much freedom they had and it wasn't much. If the choices didn't fit management's programs the door wasn't very far away. Engineering is more a pursuit of meeting product specifications (including costs) and less of re-inventing wheels. That's why forty year old bridges fall down and lemons don't only grow on trees. It's damn good engineers that can come out on top of that! Arden Allen KB6NAX ------------------------------ From: WA5CAB@cs.com Message-ID: Date: Wed, 15 Aug 2007 23:40:32 EDT Subject: Re: 6HS6 sub To: Old Tube Radios MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_be3.1aa721f5.33f52130_boundary" --part1_be3.1aa721f5.33f52130_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit I also have a BSEE (and 2/3 of an MSEE not completed because of a honey blonde), LA Tech 1969. Should have been LSU 1965 but I spent too much time in '64 playing with radios instead of studying and ended up with an all expenses paid vacation to SE Asia (plus side of the vacation trip is that I retired in '96 as a W4). But back to the subject at hand - I generally agree with Dennis and Bill. I ran the Engineering Department in a niche Oil Patch company for 20+ years. For the most part, if we couldn't afford to build it right, we didn't build it. But what Operations did with it after delivery was sometimes another story. Especially after we were bought out by the enemy, Tuboscope, in 1996. Their MBA's couldn't seem to grasp the fact that complicated equipment run through pipelines requires regular maintenance. Maybe they don't teach that at Harvard. In a message dated 8/15/2007 10:10:13 PM Central Daylight Time, bill@iaxs.net writes: > Well, I got a BSME from MIT in 1960. Would have been EE, but they tore > out > the rotating machinery and replaced it with a course in vectors. So it > goes. > > The business school folks looked down on engineers as tools of the > ruling > class. Didn't matter to me, as long as there was enough of Other > People's > Money to let me build what I thought was necessary. Sadly, that went > away > in the 70s with the oil crisis (manufactured with non-engineering > tactics). > > A letter to the editor in the Minneapolis Star-Tribune (about the > bridge) > asserted that no engineer would skimp on safety factors. I replied that > things had changed, but it wasn't published. Fact is, bridge design is > done to a list of criteria. If the bridge stands for 10 years, then the > engineering was just fine. After that, it becomes a maintenance problem, > complicated by the tripling of the population. [The greatest threat to > the quality of life is the quantity of life. Black holes for wealth are > second.] > > Today, the budget rules, as management became very reluctant to add any > "improvements." Now politicians use tax money to aid people who will > fund > their campaigns. Infrastructure falls to the bottom, as failure won't > happen in their term. New stadiums bring in money, repairing bridges > doesn't. > > So engineering isn't what it was in Victorian times, the age of brass > and > steel. A Victorian machine exudes the pride of the engineers. Today's > designs > are crippled by managers that are measured only by costs. > > That is why I lose myself in 40 year old designs, like HP and Tek, and > why > I remain a member of this list. > > Bill Hawkins > > P.S. How could I have forgotten Bobby Barmore as a contributor to this > list! > Her knowledge of old things was so great that I thought she was an old > lady. > Then a business trip allowed me to meet her at the TV station, and > things > changed. She is a delightful and sharp person, who has received as much > bad > luck as a person can have and still survive. She doesn't deserve it. So > it > goes. > > > -----Original Message----- > From: owner-boatanchors@theporch.com > [mailto:owner-boatanchors@theporch.com] On Behalf Of Arden Allen > Sent: Wednesday, August 15, 2007 12:24 PM > To: Old Tube Radios > Subject: Re: 6HS6 sub > > >....Engineering decisions are made for all sorts of reasons. The > point > is, > they're our decisions to make. Others get to second guess....... > > No disrespect intended, Dennis, but I worked for engineers for 25+ years > and I know how much freedom they had and it wasn't much. If the choices > didn't fit management's programs the door wasn't very far away. > Engineering is more a pursuit of meeting product specifications > (including costs) and less of re-inventing wheels. That's why forty > year old bridges fall down and lemons don't only grow on trees. It's > damn good engineers that can come out on top of that! > > Arden Allen > KB6NAX > Robert Downs - Houston (Web Store) MVPA 9480 (Primary email) (Backup email) --part1_be3.1aa721f5.33f52130_boundary Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ---REMAINDER OF MESSAGE TRUNCATED--- * * This post contains a forbidden message format * * (such as an attached file, a v-card, HTML formatting) * * Mail Lists at theporch.com only accept PLAIN TEXT * * If your postings display this message your mail program * * is not set to send PLAIN TEXT ONLY and needs adjusting * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * --part1_be3.1aa721f5.33f52130_boundary-- ------------------------------ Mime-Version: 1.0 From: "Kevin Anderson" Date: Thu, 16 Aug 2007 14:09:32 GMT To: Old Tube Radios Subject: Re: Boatanchors list - happy 15th birthday Message-Id: <20070816.090932.20840.1@webmail06.lax.untd.com> Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Content-Type: text/plain; charset=us-ascii Well, I've been lurking here for almost the entire 15 years, having joined in the spring of 1993 on the old AcidQueen version. I have learned plenty during my time of lurking here. I remember most of the early folks (Jim, BA Bob, Roberta, Nick, Mr. Ornitz, etc.), although I haven't met a single one in person. Congratulations on a helpful 15 years! May there be many more. Cheers/73, Kevin, K9IUA Then of Rock Island, IL; now of Dubuque, IA ________________________________________________________________________= Send your friends personalized video messages! Sign up for a FREE Juno account and start sending Video Mail today! http://track.juno.com/s/lc?u=3Dhttp://account.juno.com/s/cart?action=3Da= ddToCart%26offerId=3DfreeVideo%26sep=3Dssc%26group=3DfreeVideo%26mailTyp= e=3Dvideo%26refcd=3DJUEML0707VDO ------------------------------ Message-ID: <28763921.1187285346552.JavaMail.root@elwamui-royal.atl.sa.earthlink.net> Date: Thu, 16 Aug 2007 10:29:06 -0700 (GMT-07:00) From: spr@earthlink.net To: Old Tube Radios Subject: Re: Boatanchors list - happy 15th birthday Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Folks, I joined quite a few years ago, perhaps 10. I have learned a lot from all of you, and have I hope contributed the occasional bit of useful stuff as well. I corresponded with Bobby Barmore a bit and with she were still here. She was knowledgeable and sensible. I have actually met Morris Odell from Australia on two of his trips here, and have greatly enjoyed his company. Face time is good, when the occasion arises. Log live the Boatanchors list, and many thanks to Kack and Phil for maintaining it and its hig S/N ratio. Regards, Scott Robinson ------------------------------ From: wb3fau@att.net To: Old Tube Radios Subject: BAs -15th! Date: Thu, 16 Aug 2007 18:06:48 +0000 Message-Id: <081620071806.13986.46C492380000B2EE000036A221602806519A0E00CC0D99@att.net> Folks, sure been nice talking to all of you who watch this, as some dummy[me] lurks thru some cool old tech stuff, over the past few years. For me, i think its only about 6 or 7 years. I have been steered correct by a few of you. I have learned not to argue with some of you. I sometimes dive right in and get spanked. i have learned to listen more too! Now wheres that filament switch? Russ. PS enjoy a few 807s and some 813s. ------------------------------ Date: Thu, 16 Aug 2007 11:25:16 -0700 From: "Liles Garcia" Subject: Congratulations On Fifteen Years!! To: Old Tube Radios Message-id: MIME-version: 1.0 Content-type: text/plain; charset=iso-8859-1 Content-transfer-encoding: 7bit Good day Everybody, I, too, would like to add my congratulations to our BA List!! I think that I signed on in about 1995, and I still remember the members that are no longer on our List. Over the years I have learned a tremendous amount of information, and received a lot of very helpful assistance and advice. Many thanks to Jack and Phil for their great efforts for our List!! Please keep up your great work!! Again, many thanks, and everybody have a great rest of the week and a great weekend!! Best regards from Aloha, Oregon, Liles Garcia landn2@verizon.net ------------------------------ Message-ID: <000a01c7e055$c97f8cd0$f59d480c@KB6NAX> From: "Arden Allen" To: Old Tube Radios Subject: Re: BAs -15th! Date: Thu, 16 Aug 2007 12:42:47 -0700 MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit I joined the list, I guess, about ten years ago, don't remember exactly when. Jack put me in jail once and I got taken to the wood shed a couple of times by members who thought my etiquette was in need of improvement (just goes to show I hung out with the wrong kids on the playground ;-). Well, all's well that goes well and I'd guess this list has few peers with respect to its adherence to its mission. I've learned from many, I've swapped info now and again, and I've helped a few. It's been worth every minute of my time and I hope I'm still downloading BA postings 15 years from now. Let's keep 'em glowing! Arden Allen KB6NAX ------------------------------ Message-ID: <46C4D8CB.40208@tbc.net> Date: Thu, 16 Aug 2007 18:07:55 -0500 From: Steve Berg MIME-Version: 1.0 To: Old Tube Radios Subject: Re: BAs -15th! Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Hi All, I am not sure when I started on this list, but it was after the acid queen days. It has been a lot of fun, and I have learned a great deal. Jack has done a great job in moderating the list, and I really wish that Roberta, Barry and the others were back with us more often. It was also a lot of fun to meet Jack, who doesn't look near as curmudgeonly in person as he does when ruling the list with an iron fist. I got that power supply choke from him, and the main project this winter is to get that G-76 power supply built and working. From what I see on his APRS page, it looks like Jack is finally back home after one tremendous trip. Now, on to the next 15th! Steve WA9JML ------------------------------ Message-ID: <040801c7e062$1277b3c0$6401a8c0@reloaded> From: "Al Parker" To: Old Tube Radios Subject: Re: BAs -15th! Date: Thu, 16 Aug 2007 20:03:42 -0400 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="Windows-1252"; reply-type=original Content-Transfer-Encoding: 7bit Hi folks, Well, since we're reminiscing -- I got in about 13 yrs ago, when I was "temporarily" living in the SF Bay Area for about 4 yrs. For a yr or 2 then I was away from home 2 nites a wk on business, in Reno, NV ( not monkey business), and remember reading the posts after dialing in on my laptop in the evenings (kept me outta the casinos?). I've met quite a few of the originators, and members, both out there in the Bay area, and back here in eastern NC. I think Jim L, now K4CCF, was the first, at a Livermore Swapmeet, he volunteered some info on the SP-44 that he spotted in my carry bag. Then members Arden Allen, and Les Zwiebel (who later visited us in NC), plus several other Bay Area denizens who frequent the list. Back "home" in NC I came across Nick E, who I remembered from living here earlier, & John B, now K5MO, who both were from the beginning, and another bunch of regulars incl. JP, K4OZY, and The Shelby Regulars, rm the Rocket Man, etc.. Barry O. was a treat to meet, and to know for the last 8-9 yrs, tho' haven't kept up with him for the last 11 mo.s since last Shelby. I've probably missed mentioning a few. It's been a great time, thanks to all for making it happen and keeping it so nice, and helpful. I also hope to be here for another 15 yrs. 73 all, cu soon, Al, W8UT New Bern, NC www.boatanchors.org www.hammarlund.info ------------------------------ Message-ID: <380-22007851745412140@earthlink.net> From: "Art Lebermann" To: Old Tube Radios Subject: RAO-7/9 receiver info? Date: Thu, 16 Aug 2007 21:54:12 -0700 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Do we have any experts on the RAO series of receivers? I have an RAO-7 receiver, and recently found an original NAVSHIPS instruction book for the RAO-7 and the RAO-9. A review of this manual has answered one question, and raised another. I've never been sure of the differences between the RAO-7 and the RAO-9. NAVSHIPS 900,356 (12 Oct 1945) states that the RAO-9 is the same as the RAO-7 except that "the RAO-9 is designed to be relatively unaffected by interference from nearby electronic apparatus". A review of the schematic and parts list shows only one difference between the two models. The RAO-9 has a 30 K ohm resistor and a 50 mmf capacitor in parallel, connected in series with the grid lead of both the first and second RF stages. The RAO-7 has the grids of V101 and V102 connected directly to the tuned circuits. So, my question now is - how do these parallel RC networks improve the performance of the RAO-9, as claimed in the manual? And what sort of "interference" are they talking about? As all but the first two RAO models have an added RF stage in a separate shielded housing, I would assume that these receivers were already above average when operating in a difficult RF environment. If anyone would like a partial schematic, with the "mystery" components noted, contact me off-list and I'll send you a PDF file. 73, Art Lebermann W6REQ ------------------------------ From: WA5CAB@cs.com Message-ID: Date: Fri, 17 Aug 2007 01:25:45 EDT Subject: Re: RAO-7/9 receiver info? To: Old Tube Radios MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_c3d.1a9f5ac8.33f68b59_boundary" --part1_c3d.1a9f5ac8.33f68b59_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Art, They are talking about front-end overload caused by high power transmitters operating on a nearby frequency and using antennas physically close (less than a few hundred feet separation) to the receiver antennas. High power for shipboard transmitters of the period generally meant around 500 watts output. That was pretty much the standard into the 70's when the AN/URT-23 came out. In a message dated 8/16/2007 11:55:02 PM Central Daylight Time, artleb@earthlink.net writes: > Do we have any experts on the RAO series of receivers? > > I have an RAO-7 receiver, and recently found an original NAVSHIPS > instruction book for the RAO-7 and the RAO-9. A review of this manual has > answered one question, and raised another. I've never been sure of the > differences between the RAO-7 and the RAO-9. NAVSHIPS 900,356 (12 Oct > 1945) states that the RAO-9 is the same as the RAO-7 except that "the RAO-9 > is designed to be relatively unaffected by interference from nearby > electronic apparatus". A review of the schematic and parts list shows only > one difference between the two models. The RAO-9 has a 30 K ohm resistor > and a 50 mmf capacitor in parallel, connected in series with the grid lead > of both the first and second RF stages. The RAO-7 has the grids of V101 > and V102 connected directly to the tuned circuits. > > So, my question now is - how do these parallel RC networks improve the > performance of the RAO-9, as claimed in the manual? And what sort of > "interference" are they talking about? As all but the first two RAO models > have an added RF stage in a separate shielded housing, I would assume that > these receivers were already above average when operating in a difficult RF > environment. > > If anyone would like a partial schematic, with the "mystery" components > noted, contact me off-list and I'll send you a PDF file. Robert & Susan Downs - Houston (Web Store) MVPA 9480 (Primary email) (Backup email) --part1_c3d.1a9f5ac8.33f68b59_boundary Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ---REMAINDER OF MESSAGE TRUNCATED--- * * This post contains a forbidden message format * * (such as an attached file, a v-card, HTML formatting) * * Mail Lists at theporch.com only accept PLAIN TEXT * * If your postings display this message your mail program * * is not set to send PLAIN TEXT ONLY and needs adjusting * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * --part1_c3d.1a9f5ac8.33f68b59_boundary-- ------------------------------ Message-ID: <380-22007851753928578@earthlink.net> From: "Art Lebermann" To: Old Tube Radios Subject: Re: RAO-7/9 receiver info? Date: Thu, 16 Aug 2007 22:39:28 -0700 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Any idea how the RC network at the grid of each RF stage would reduce the effects of front-end overload? ART W6REQ > [Original Message] > From: > To: Old Tube Radios > Date: 8/16/2007 10:26:40 PM > Subject: Re: RAO-7/9 receiver info? > > Art, > > They are talking about front-end overload caused by high power transmitters > operating on a nearby frequency and using antennas physically close (less than > a few hundred feet separation) to the receiver antennas. High power for > shipboard transmitters of the period generally meant around 500 watts output. That > was pretty much the standard into the 70's when the AN/URT-23 came out. > > > Robert & Susan Downs - Houston > (Web Store) > MVPA 9480 > (Primary email) > (Backup email) > ------------------------------ Message-ID: <023b01c7e0b3$db7abb90$640fa8c0@radioroom> From: "Tom Rauch" To: Old Tube Radios Subject: Re: RAO-7/9 receiver info? Date: Fri, 17 Aug 2007 05:49:00 -0400 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit > Any idea how the RC network at the grid of each RF stage > would reduce the > effects of front-end overload? The only way it could do anything is by biasing the grid negative when the grid draws grid current. It would be interesting to see how that affects blocking and intermodulation. The Drake R4C does something very similar. It has a resistance in the grid AGC path, and the capacitor in this case is in series with the input circuit. When a very strong signal (like a local transmitter) causes the RF amp to draw grid current the rectification self-biases the control grid. This reduces mixing in the RF amp, but it increases desense or blocking. My guess would be they decided blocking or desense was less problematic than intermodulation. I've found the opposite to be true in my environment. 73 Tom ------------------------------ Message-ID: <46C5BA85.7050302@ar88.net> Date: Fri, 17 Aug 2007 11:11:01 -0400 From: Al Klase MIME-Version: 1.0 To: Old Tube Radios CC: Old Tube Radios Subject: Re: RAO-7/9 receiver info? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Art Lebermann wrote: > Any idea how the RC network at the grid of each RF stage would reduce the > effects of front-end overload? > > Yes, it's grid-leak bias. If a strong signal, perhaps one that never makes it through the IF to activate the AGC, drives the RF amp into grid current, a negative voltage is generated across the 30K resistor, and biases the tube to a lower gain. It amounts to local (just the one tube) AGC. I wish I remembered where I read this. It might have been one of the James Millen blurbs in 1930's QST's. Regards, Al -- Al Klase - N3FRQ Flemington, NJ http://www.skywaves.ar88.net/ ------------------------------ Message-ID: <005e01c7e112$466da440$afc3f904@b4g4z8> From: "PHIL" To: Old Tube Radios Subject: Re RAO-7/9 Date: Fri, 17 Aug 2007 17:04:59 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Going from memory which is not that good, I seem to remember the RAO-7 had the National NC-100 type cabinet while the RAO-9 had the Navy cabinet. The Navy had better shielding. Someone with better memory my clear this up Phil ------------------------------ From: "TChirhart" To: Old Tube Radios Subject: Vintage/Rare? Morrow Radio MFG CO VHF Low Band Portable! Date: Fri, 17 Aug 2007 17:11:02 -0400 Message-ID: <000001c7e113$20334e50$6402a8c0@warnerp93v1mse> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable I know that there is very little information out there on the Morrow = Radio equipment. Morrow was only in production for about 4 years from what details I have been able to find. Recently I stumbled upon what was in about 1958/59 portable low band transceiver. (portable IF you think of = what a portable was in the late 50's) The manufacturer is Morrow Radio and = the model is "Radiophone Model FLP-2IH". The unit is square with a front = panel that is removed to show a 0-200 milliamperes meter and the control knobs = and a microphone and microphone jack. The two knobs are typical Morrow = knobs. It has four switches S-Meter On/Off, Squelch On/Off, ANL On/Off, and power On/Off. Two controls, one is a 6 position switch marked RCV, A-BATT, B-BATT, OSC, GRID, and FIN. The last is a volume control knob. There = is a clear indicator lamp that apparently lights up when the power is = applied. There is a small 2.5 inch built in speaker. Overall size is 8.5"W, = 15"L, 9"H. There is a battery tray that is removable and it is 8.5"W, 15"L = and 3"H. The battery tray is removable. There is a carrying handle on the = top. There is a property tag for the Pennsylvania Forests & Water Radio with = a serial number. I have some Morrow equipment but have never seen a = commercial application built like this one. There is a paper tag that indicates it = was operating on 31.660Mc. It has a total of 16 vacuum tubes, most are = 9-1U4's 5-3A5's 1-1A3 and 1-3V4. The microphone is unique to the unit, it's a = short cylinder with a simple push button switch. I will post photos in the = near future on a website. Is there anyone out there with any information on this particular VHF LB radio made by Morrow? It's an interesting piece. =20 Thanks 73 Tom K4NCG ------------------------------ End of BOATANCHORS Digest 4079 ******************************