We Ain’t No Engineers

We love to sell parts. Let me correct that. We love to sell the right parts.

We get calls from many customers who, after looking at our web site decide they can’t decide what to buy. That’s ok. We have some experience with parts.   They tell us about their equipment and what happened and what they think they need. But… they aren’t sure.

… four of us are ham radio operators with over 100 years of experience…

Now we have touched a lot of parts and equipment; four of us are ham radio operators with over 100 years of experience in that area. We’ve touched almost every piece of ham radio and test equipment made in the last 60+ years at some point or another. We’re pretty strong in the analog area and we even have one guy who has heard of digital and can talk some digital. We know a little about RF; both low and high power. Yes, we’ve burned up a few parts but we’ve probably successfully repaired more equipment than the average shmoo.

So what’s the problem? Well, we probably can fix the broken equipment but it’s hard to do over the phone AND we don’t know what was going on when it died AND we can’t use all our senses and test equipment to evaluate what’s ‘on the bench’. You the customer must do that. Also, there is the time thing. Someone once said “time is money”. We cannot troubleshoot your equipment on the telephone. We do not repair equipment, other than our own. Another problem with asking us to troubleshoot over the phone is, what happens when we are wrong. Now you purchased a part that we recommended and it didn’t bring your equipment back to life. That sets up a bad situation that there is no happy ending to.

Get some help. Seek another opinion from someone who’s on the scene and has some knowledge. More information is available online today that can assist with almost any repair. Contact the manufacturer. Study the manuals. They say that people who ask for advice are seeking an accomplice. That may be true but additional insight almost never hurts.

I am personally a cheapskate. If I can fix it at no cost I’m there. Many times that’s not possible so I have to buy parts. I do so cautiously so as not to buy parts I don’t need… just like you.

Many times we get calls about parts that we don’t have because they were specially made one time only for that piece of equipment. Just because we have boat loads of weird one off parts does not mean we have the part you need. Sometimes, you can only get those parts from the manufacturer – if he still has them in stock for the thing they made 30 years ago.

Sometimes…

Sometimes the calls are about parts the customer can get from the manufacturer and the parts seem extremely high priced. It may be because they were expensive to make and/or the manufacturer controls the supply and has priced them accordingly. These parts are usually marked with cryptic part numbers that don’t relate in any way to the value or function of the part. Sorry, but we can’t usually help with that.

Sometimes that piece of production equipment was made a long time ago and now that it’s broken it’s time to replace it with something that can be repaired.

These are all economic questions that can mostly be answered by the engineers and, unfortunately sometimes, the accountants. You might even have to involve management.

Please don’t call us to try to place us in any of the roles just mentioned. Mostly what we know is our parts and sometimes we know what they’re used for.

Call us about our parts and we’ll tell you what we know about them. We pretty much put everything we know about a part on our web site but don’t be surprised if we miss a fact once in a while. We have about 100,000 parts (line items, not part count) on hand and listed on our website. Another 100,000-200,000 have been purchased, now sitting in boxes in our warehouse. Slowly, they emerge, as time permits, and get cycled through our system to bring them up on the website. It is of no use to call us about parts you hope we have, that are not found on our website. Watch and search the site often. It changes daily. Dozens of items are added and subtracted each day of the week.

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What is a Transfer Relay?

Guest Writer: Bill True, WA9ASD

That’s when you get on a bus and buy a transfer so you can give it to your buddy to use to ride his bus to work for the cost of a transfer. Well, not exactly. If you Google “Transfer Switch” most of what you will find are AC power transfer switches. These are used to switch your AC power from the power company to your backup power source; generator, solar panels or battery backup. If you have a home AC generator your power company will require one and your local building codes people will have to certify it. It could be manual or automatic. We offer a Generator Transfer Switch. 

Is it a switch or a relay? The answer is confusing. My answer is as it pertains to Surplus Sales. A switch is a manually operated device.  Contacts are actuated with a twist or flip of a lever. It must be physically switched. A relay has a coil with a set of contacts operated by an armature. apply a voltage and cause a change in the position of the contacts. Switch: manual; Relay: electric.

Amphenol 300-11002-2 Transfer Relay

Amphenol 300-11002-2 Transfer Relay

An RF Transfer Relay allows you to connect 2 transmitters to 2 loads. One to a dummy load and the other to an antenna. When the relay switches the two transmitters are swapped between the antenna and dummy load. Another way to look at them is to consider a 2 position switch with ports 1, 2, 3 and 4. At rest port 1 is connected to port 3 and port 2 is connected to port 4. When activated the connections reverse. Port 1 is connected to port 4 and port 2 is connected to port 3. Broadcasters use these to connect both their main and backup transmitters to the antenna/dummy load for almost instant changeover to the backup transmitter. It can also be used to control the antenna connection to a transmitter and receiver. In the “at rest” position the receiver is connected to the antenna and the transmitter is connected to a dummy load. By switching on the relay when the transmitter is activated the antenna gets connected to it and the receiver goes to the dummy load, protecting it from the strong RF from the transmitter.

Another kind of reverse (perverse?) usage is to provide automatic grounding of an antenna when not in use. Whenever the transceiver is powered-up the transfer relay is activated connecting the transceiver to the antenna. When the transceiver is turned off the transfer relay de-activates connecting the antenna to ground. The same thing can be accomplished with a knife switch for open wire feed lines.

We have a couple of very high quality “N” Transfer Relays available from some of the most highly regarded manufacturers; Amphenol, DowKey and Transco (now a part of Dow Key Microwave). SMA Transfer Relays by DowKey. C connector Transfer relays.  EIA Transfer Relays for the Broadcasters.  Waveguide style Transfer Relays.

As you can see, transfer relays can be an important and valuable addition to your station. Call us if you have any further questions.

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Teaching this old dog new tricks – Who needs social media?

I have been drug into the 21st century kicking and screaming. We always put out a decent catalog through the years. That is as far as small surplus houses are concerned. I bought the very first Macintosh 128, then a Mac 512 followed by a Mac Plus and on and on. BTW, we have never sold a retired computer. Not worth much. Great start for a museum. For software, Pager Maker was mastered and soon replaced the paste up catalog pages. If you’re not familiar with what paste up is, we literally clipped words and sentences out of catalogs, along with low res photos, pasted them all on an oversize page and added self adhesive black border lines. Then the printer would photograph the page and reduce it. Long about 1997 our last 400-page printed catalog fell to the Internet and our first website. My advertising department grew from one man to a two horse shop with a full time webmaster. That model more or less propelled me into the second decade of the new millennium.

Then a brick wall I did smack. The wheels fell off. We had not followed the rules. The website schematic that had proven fruitful for so many years all of a sudden took ninety ninth fiddle to more sophisticated sites and overnight our ranking on the average search slid to frightful depths down the search results. SEO. I thought that was like a Senior Executive Officer. Me of course. By the time I figured out it meant Search Engine Optimization, I was the last donkey out of the barn. Businesses exist whose sole purpose is to make web pages occur higher in the search. I know of several great companies that do just that in our Mastercraft Building. Perhaps I should have used one of them. Nah. That would be too easy. We can do all that ourselves. Eventually.

We are nearly finished with a full revamp and making our website more social media friendly and hope to be able to get back to selling parts like we have for 39 years. I will take a moment or two, from time to time, to write in this blog, and will try and share experiences that may be interesting to others. Many of us here at Surplus Sales will contribute. We have a collective 150 years in experiences to write about. Our intention is that new customers as well as those that have been around for the long haul might learn something about us that they didn’t know.

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6888 – A Pentode in Hiding

Guest Writer: Bill True, WA9 ASD

 

surplus-sales-pentode

There are a number of tubes that appear to be ‘under the radar’ of tube equipment designers for no apparent reason. One such tube is the Sylvania 6888. Originally designed as a core driver in first generation vacuum tube computers, it is practical in several other applications.

Multiple versions of a one or two tube AM Broadcast Radio project might be responsible for bringing this tube back in demand. We found a half dozen worthy construction challenges on the Internet. The 6888 is used for an AM transmitter to feed a signal to antique table radios. Using modern input sources, we think there is an un-tapped potential as a low power audio application like a headphone amp or personal stereo as well. If availability or cost were deterrents in the past, we now have enough to go around. With over 10k in stock we offer a 1 each price of only $3.95 and it drops to $2.50 ea for a whole case of 100 at a time. See our tubes at SurplusSales.com

 

Let’s skip the paradoxical complication of a wireless connection and the questionable sound reproduction of antique radios and go right from source to speaker. No limitation of 5 Kc on the top end that AM stations are subject to. No misaligned IF section that misses the detector pass band. No risk of leaky filter condensers and torn paper speaker cones. Let’s just put a little gain and some impedance matching between the source and some good, wide-range headphones or speakers. Worst case; hide the good speaker in the antique radio.

While the 6888 is kind a power hog on the filament side it is definitely a pussycat on the plate side with moderate if not low voltages and current required. Because of this it shouldn’t need some exotic hand-wound high plate impedance transformer to match the load. A couple of thousand Ohms ought to do it.

As a voltage regulator, another great idea for this pentode, it should be nearly indestructible and will probably out-last the resistors in the circuit. It would have considerably more current capacity than a VR-150. We will be happy to post on this site any project using the 6888 and give credit to the author.

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