I’ll have a couple of MN-4 tuners for sale or trade at hamvention. ? They are nice shape, one with orig manual too. ??

Come by and say hello ! ? ?Flea market space
?7275?

hope to see you there !?

Joe K9UR?

Hello all,

After a week of distraction - repairing an SBE SB-34 - I turned my attention back to the TR7. Time for an alignment. I had set up a proper bench, with a 5-foot shelf for test equipment. I had also
installed an LED tape under the shelf, so the entire bench is bathed in light.



To prepare, I printed out the alignment procedure. I have found two scans of the Service Manual on the net; one is complete but low quality - all the pictures in black & white ( no shades of gray ). The other one is grey-scale with usable pictures; but it is missing the first page of the alignment procedure. So I printed out the first page from one, and the rest of the pages from another.

I also took a picture of the rear circuit boards with the shield panel removed. Printed it on the color laser, and wrote the designators of all the adjustable stuff on the printout. When I opened the radio, I noted a lot of flux on the parent board; A half hour of quality time with Q-tips and IPA made it much nicer.

Getting started, the 10V was 10.35; I set it to 10.00 with my most trustworthy DMM - an almost
new Fluke 87V. That committed me to doing the complete alignment, but I was planning to do that anyway.

My new ( to me ) HP 5385A frequency counter performed admirably for setting the oscillators. Ran into a little problem with the 8.05MHz oscillator; the adjustment cap didn't
have enough range. There's a cap in parallel with it, and the manual advises that you can change that one. 10 caps and 2000 years later, it was dead nuts on. First, I was adjusting it the wrong way - it's subtractive mixing, duhhh. Then with out realizing it, I moved the PBT control in the
heat of battle, and kept adjusting...

One problem was that I didn't have the right size tuning tool for the small adjustable inductors. I used to have every tuning tool known to man, but that was years ago, and they seem to have gradually dribbled away. Back in my misspent youth, I worked in an instrument shop
for a few years, doing repair & calibration.... lots of peaking & tweaking back then!

I discovered that I can tune those cores with one of those screwdrivers with a plastic body & a metal tip; the ones that have an exposed metal tip at one end, and a recessed one at the other end. Two sets of tuning tools on order; one from GC Electronics, and the other one from China Inc.

Luckily, I had replaced all the power supply pots with 10-turn units. Wow, the adjustments are
pretty twitchy. No idea how one could do it with the original 3/4-turn units.

Now at the VCO calibration. The manual advises that you don't have to do it if the unlocked VCO is "about 17MHz" on 20M, and "about 32Mhz" on 15M. Well, those numbers are 18.12MHz and 33.62MHz. So I guess I should probably do it. Need to get into that area anyway to clean connectors.

In addition to the alignment, I have in hand a new 2.7kHz filter from Noble Radio. Going to install that as the default SSB filter and move the stock 2.3 to another slot.

- Jerry, KF6VB

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On Wed, May 17, 2023 at 02:00 AM, Steve Wedge, W1ES/4 wrote:

Perhaps that wasn’t the case when the bulletin was written.?

?

Steve Wedge, W1ES/4

?

Time flies like an arrow. Fruit flies like a banana.

?

?

Sent from Proton Mail for iOS

?

?

That would make sense I guess.....?

I did do a search of different vacuum tube providers and just all of them listed the 6AQ8? as available but the prices were a little "out there" compared to the 6EV7's I found.? Many (or all) listed the 6EV7 as available too (including used and/or NOS on eBay) starting at $10-15

There's one seller on ebay that's selling 10 NOS 6EV7's for $50 + $10 shipping (+ tax of course)?? Making them about $7 each.

But for a double triode tube that is only used for something as simple as a VOX amp and relay driver, It appears that other subs good choices too.....( 6FQ7, 6GU7 )


?
--

73/Rick

WA6III
*Every post is created using Linux

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No wonder I can't find any W4's at the local fest anymore. You have cornered the market on them.?

Mark, WB0IQK

--
Chuck Rippel, K8HU

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Oh please John!

Really?

Jim W7RY

Charge USPS/UPS counter rates, and pay PirateShip/commercial account rates. It's a good way to skim a few more bucks from the buyer.

John K5MO

On Tue, May 16, 2023 at 6:19?PM NU2W <oemeoc88@...> wrote:

A flipper indeed…crazy shipping fees…NO TU!

?

STAY SAFE AND STAY WELL!

Respectfully,

Thomas K. Lanieri, NU2W

NJ Licensed EMT; PHTLS, AMLS, PHPEC

B.A.A. EMS Support

ARC N.E. BioMedical Services

ARC N.E. Disaster Health Services

DanaFarber-Am Cancer Society

?

From: [email protected] <[email protected]> On Behalf Of Chuck Rippel - K8HU and ex - NMN
Sent: Tuesday, May 16, 2023 4:42 PM
To: [email protected]
Subject: Re: [DRAKE-RADIO] NOS TR-4Cw RIT

?

If you go to his E-Bay "store," there are a number of Drake items in "As New" condition.

?

Looks like a radio-flipper to me.

?

?

Chuck, K8HU

--

"The Constitution does not authorize agencies to use pan-and-phone regulations as substitutes for law passed by the peoples representatives."

~ Justice Gorsech, Concurring Opinion

?

Virus-free.

--
Chuck Rippel, K8HU

These TR-4CW rigs on ebay have been interesting to me. ?I bought one locally about a year ago, a TR-4CW with RIT. ?it is not in good shape, has some rust spots at a couple places on top, and it doesn’t turn on. ?The AC-4 needs to be recapped, so it’s hard for me to do much without it. ?For various reasons, I’ve decided not to keep it. ?A “mint” rig went for $2400 a month or so, and the current one seems to be going that way. ?On the other hand, one that had a loose mode switch but would turn on just went for $199.95. ?That’s so low that fees, packing, and shipping would be a high percentage of the price.

?I sold the rusty RV-4C that came with mine and basically broke even after I agreed on a price and then found out what shipping would be. ?The price of shipping has been a game changer for these kinds of rigs, and where I shipped it said they would not provide insurance unless they packed it. ?For the RV-4C, that means I would have gone in the hole by quite a bit so I packed it myself.

?The bottom line is that if someone is interested, I would be glad to send pictures and talk about it. ?I was the second owner of this rig and should have kept it. ?Now, I am again about the fifth owner and would like to see it go where it could be fixed and appreciated. ?

73,
Dennis, W5RZ

I sanded my MN2000 and sprayed a few coats of primer and a few coats of satin black. I struggled to get a uniform application from the can so decided to try rolling on the final coat. I got a nice stippled finish that I think closely matches the original. Expand the attached photo to see the texture. I used a 4” high quality roller (avoids lint) with 3/8” nap. Key to a good result is bright lighting all round so you can see that you have rolled consistently on all sides. Get the paint applied uniformly all over first then roll outward to all edges to get a uniform texture. You still have to spray a few coats first to cover certain areas that a roller can’t reach such as the inside of the rolled front edge of the case.
--
73
John?N9FCA

On 2023-05-17 05:42, Gregg Lebovitz wrote:

Besides Drake equipment I have bought other ham equipment from estate
sales. I bought a cantenna from an estate sale and they packed the

The Cantenna is a messy item. I bought one at the flea market. It
was filled with some unknown oil. I carefully decanted it & cleaned it
out - disposed of the oil at the local hazardous waste facility and
refilled it with mineral oil. Then put it in a bucket with a hole
for the coax.

- Jerry, KF6VB

Besides Drake equipment I have bought other ham equipment from estate sales. I bought a cantenna from an estate sale and they packed the whole thing including oil in a box and sent it. I paid $20 including shipping and assumed they removed the oil. What I received was a package that was on oily mess. Had it tested for PCBs and it was negative thank heavens. You need to be careful when buying from non hams.