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 91 
 on: June 23, 2017, 11:40:53 AM 
Started by N3DRB The Derb - Last post by DMOD
I think there must be a typo in the last formula unless I missed something in the article.

I think C1 has to be XC1, otherwise, the value for C2 is non-sensical.

Let's assume values for an 813 stage:
Bplus = 2000V, Vsg = 350, Isg = 35e-3, XC1 = 42 ohms for C1 = .001 uF at 3.75 MHz then:


R1 ~ = 79k (rounded up)

R2 ~ = 120k (rounded up)

C2 (with Faudio = 10 kHz) ~ = 0.22 uF (nearest standard value).

The 3 db down point of R1C2 is 9 Hz.


If C2 = 0.6*(1/(twopi*10e3*C1)), then C2 =  9.6 kiloFarads and the

3 db down point would be 2.1e-10 Hz.


Phil

 

  

 92 
 on: June 23, 2017, 10:45:37 AM 
Started by W7POW - Last post by Todd, KA1KAQ
An all too familiar tale for me as well. When I moved in '94 I was off the air for a decade before getting a wire back up in the air. Listened a lot but it was 'hearing' what was going on via 'fone that really lit a fire under me. Moved south in 2008, only a year +/- before getting back on, though never got things finished. Moved here last July, got back on 40m a couple months back thanks to the help of W3JN and his not-so-EZ-Hang launcher. Still have a long ways to go.

Throw a wire up ASAP. Get something on the air. That will motivate you to do more, sooner.

Good luck with it.

 93 
 on: June 23, 2017, 10:40:56 AM 
Started by Todd, KA1KAQ - Last post by Todd, KA1KAQ
A couple shots of the R-12T...

 94 
 on: June 23, 2017, 10:38:40 AM 
Started by Todd, KA1KAQ - Last post by Todd, KA1KAQ
Heh, it's only been about 3 weeks since the hamfest, finally getting a chance to post. Been traveling a bit since.

So the event was indeed a small-ish hamfest as I'd always heard. One day only, and a Sunday, at that. Like the Richmond FrostFest though, they let sellers come in the day before to set up which is always nice. In this case, moreso since they fairgrounds are less than 5 miles from my driveway.

Some of the AM crew came by for a cookout Saturday and to set up, then Sunday we went a-festin'.

I have to say - also as I had heard in the past, this little event was a target-rich environment. Still amazed at what showed up and the prices. Very little computer or other junk, mainly RF-related goodies and sellers who were motivated to move it.

'GMS was the Table-Meister for our group and got us two tables inside out of the sun. Joe and Martha moved a BUNCH of stuff fast, and I did see Joe snagging a few goodies to take home. W3JN aka Johnny Novice was on the prowl for receivers and found a couple very nice ones that were well above my paygrade technically. John is still working to sell the remaining items from KB3AHE/Slab's estate for is wife Carol, too. Frank clearly had a lot of stuff, and 'JN has a lot of patience and dedication to the task.

For my part, I managed to move a couple of old wooden radios from the collection that I'll never get to. One was a Stromberg-Carlson, the other was a farm radio whose manufacturer I've forgotten. I was dtermined to sell, sell, sell and not buy anything, which worked fine for....the first 20 minutes or so.

Walking the grounds with 'JN we came across a pile of mixed gear. John sez "There's a GR mod monitor back there". Sure enough, a black crackle model 1931A in great shape with original manual. Price was good but my scottish blood made me offer $20, which was accepted. This was followed shortly by an early brass-based, tipped WD-12 tube on a table for $5. 'JN also found a couple old tubes for a buck apiece from an outdoor tube vendor which he snagged for me, a UV-199 and 800. Then I bought some rubber feet and got a sample packet of other goodies from the seller who is a member of MAARC.

All this time I'd been walking past a Halli R-12T table speaker with light damage that the seller was asking $75. Tempting, but too much $. Cabinet and trim were nice, original speaker with cord and tag in place, but grill cloth was torn, small tear in speaker cone as well, and a piece of veneer missing from the R. All easy to address. 'Too much $, you say? How about $45?'. Sold. Not that I needed another project, but I've always wanted one of these speakers. It's a HUGE table speaker.

Saw Fran/W3SCC and a few other AMers there. Also got to meet a couple folks known previously either online or on air. We loaded up sometime after noon and called it a day. Jen had a school graduation to attend so she brought my co-pilot by and dropped her off for the last half hour or so. Caitlin made about 1/2 tour of the inside building before saying "I think we've seen enough, let's go back to the table" so she could hang out with Joe & Martha more.

This is a great little hamfest, a lot like Berryville in the 'good stuff to sellers' dept, a very high ratio. Best of all, it was another chance to get together with friends and socialize a bit. Just need to work more on the 'selling stuff' side.

Photos attached of my haul. One of the good things about still not being completely unpacked is the ability to make stuff blend in to its surroundings like it was always here....  Wink

 95 
 on: June 23, 2017, 10:00:29 AM 
Started by KB2WIG - Last post by Todd, KA1KAQ
I'll agree with the Budster and add to this as another who missed out on most of the Heathkit era (did use their SMT course). While it wasn't TMC, Collins, or even EFJ design quality, it surely wasn't bad. Take a look inside the Apache sometime at those big, black blocks. Also the DX-aHunnert. Or the Mohawk (though not a good AM receiver in stock form). None of these rigs are cheap or cheesy. More that, like anything else built by a number of different people, it's all about the build quality. Even the AT-1 and AR-3 I have aren't as flimsy as other equipment of the period.

As time progressed, all of the US manufacturers suffered from quality as well as design issues and most eventually went out of business. Hammarlund, Hallicrafters, National, etc. - gone. It's not unique to Heathkit.

While I'm glad someone is trying to ressurect the name, it's too bad they appear to be relying on the sideshow-carny approach for hyping their product. Perhaps due in part to the high price they're asking, they need to make it seem like all that and a bag of chips. Apples and oranges compared to the old gear, though.

 96 
 on: June 23, 2017, 09:54:04 AM 
Started by ka1tdq - Last post by ka1tdq
...and in all its glory

https://youtu.be/WF2XivrDuLU

Jon

 97 
 on: June 23, 2017, 09:47:51 AM 
Started by KB2WIG - Last post by WD8BIL
I have to agree with most of you. Heathkit gave many a young JN the chance to have a reasonably good station without the cost. Building and reading the theory of operations provided a source of knowledge not readily available in jr. high and high school which, by the way, was part of their "mission"!

I built many of their kits for myself and others. Let's see; (3) HW101s, (2) 2036 2meter FM rigs, (4) SB200s, (1) SB220, (5) HM102s, one of their 50 MHz frequency counters, (1) Color TV, (1 set) AS-1352 stereo speakers still in use today, (1) engine analyzer scope, (1) digital clock still in the shack and working fine.

Was it the highest quality stuff? No. But it was never meant to be. To judge them out of context shows little appreciation for the knowledge and fun Heathkit provided the masses back in "the day".


 98 
 on: June 23, 2017, 08:30:13 AM 
Started by KB2WIG - Last post by ka1tdq
My first and only piece of Heathkit gear was a HW-9 QRP transceiver. I wish I still had that one. I left it at father's house when I joined the military 20 years ago. I've asked about it but he can't remember anything about it, and they've moved several times. I'm sure it's layers down in a landfill by now.

Jon

 99 
 on: June 23, 2017, 12:21:14 AM 
Started by KB2WIG - Last post by nq5t
My very first piece of electronics (aside from a Cub Scout crystal set) was a Heathkit V-7A that I still own and use, by the way.

Then an Ocean Hopper (non-Heath of course), followed by an AR-3/Q-Mult, DX-20, and then a DX-40 (and shortly thereafter an Eico modulator), and an Apache.  For many years after that, I built a lot of Heath test equipment, but no more radio gear.  And then around 1970, the SB-102 was released . and that started it all over again.  My wife sold her Martin guitar and bought me the radio as a Christmas present.  Wish I knew if the radio and all of the accessory units I eventually built were in a landfill somewhere or still gracing someone's shack.  I should have put my call somewhere on the chassis.  Used that radio almost 10 years .

To this day, I fondly recall the fine aroma of the (original) Heathkit boxes when you first opened them up.  It was almost magical.  Nothing else like it :-)

 100 
 on: June 22, 2017, 11:23:22 PM 
Started by KB2WIG - Last post by K1JJ
Ahhh, Heathkit.  I have a few stories...

Back in 1967 I built the Heathkit Starmaker 60 watt guitar amp. Nice amplifier. We started a group called the "Motown Review" and actually played two paying gigs. My career ended when the drummer accidently walked into my propped-up guitar and broke the neck. It's true that the girls were at every gig (two) and were EZ pickings for us teen "rock stars."

I remember seeing the insides of an SB-300 Grief-kit that was built using acid core solder. There was acid leakage all over the boards.

Then there was a ham store that took trades in the late 70's. After a while Heathkits dominated the used shelves. Mostly SB XXX series. Nobody wanted them and they were a nightmare to fix and guarantee - ghosts that kept haunting and coming back. The store finally refused to take any more in trade. That inventory stayed around for a long, long time.

Speaking of kits, I was always amazed how little the $ difference was between factory wired and a kit, ala Johnson's Viking series. But all in all, Heathkit had a wonderful business through the 50's, 60's and 70's that got many guys started for cheap and many went on to build up more complex homebrew rigs as a result. The ham whirl is a better place due to Heathkit's existence. Who could axe for more?

Is this the same Heathkit trademark owner who was promoting some other Heath product a few years ago? What was that about and how did it work out? There was a similar uproar about the sales hyperbole.

T

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