Made me think of Enzo

[Randall]

There are some very intelligent people in this forum. And I am a very happy reader of their offerings.

[Joe L]

There are some very intelligent people in this forum. And I am a very happy reader of their offerings.

I totally agree! I find that most people just perform at the level they do because their profession makes them money. It's obvious that the people on this forum love electronics and solving problems. You can't ask for a better combination.

[km6xz]

Joe, 4 more days....
Not all contractors are bad. I had a side business in the 70s that was located 135 miles from my main business. It was a communications gear repair service in the mountains of rural eastern central California. I had property in the area and was captain in the largest all volunteer fire department in the country....I was made captain solely because I was the only one who could keep the old low band VHF gear going and donated lots of surplus Motracs to them.
I was hired to consult on designing a new system for the US Forest Service that was going to be experimental, solar powered and paid for by a grant from DOE. It was more hobby than anything for me because my business on the other side of the state kept me busy much of the time. I commuted by flying or driving once or more times a week. One of the things I included in the design proposal was a solar powered refrigerator for one of the higher live-in lookout towers, besides a repeater system with microwave links between 8 mountain top repeaters. It was the first solar refrigerator and actually worked pretty well. It could keep ice from melting but would take a long time to freeze anything. But it was not intended to, only to keep fresh foods from spoiling for the 1-2 weeks a lookout lived there between off time when more food could be bought.
Late one afternoon, I got a call from a desperate dispatcher who relayed that a fire had broken out that was in vertical canyons along south of HW50 in a difficult area, being pre-fire-season no helitack crew or aircraft were activated yet, it was going to be all handcrews. The problem is the old repeater that covered that area was off the air and the civil service radio tech, as usually, was not answering his phone or door when off duty. He was about to retire and had delayed installing the new system 6 months because he was retiring in another 4 months.
They had no coverage in the area and the old system was burned by the fire while the new system sitting in a warehouse for the prior 6 months in crates. I had a break in my session for a few days so flew my Piper Arrow to Placerville , went to the warehouse and talked my way into the area with the new gear, and commandeered one of the repeaters, deep cycle batteries, a Super-StationMaster downtilt, 4 can Hi band duplexers, heliax and all I could stuff into my FJ-40 Landcruiser with the Station Master lashed to the top. I had only the friendship relationship, no contracts or business connection after the consulting was done months before but the dispatcher had my phone number. I reached the area by nightfall. The fire was pretty much burned out at the top of the mountain where the repeater was located but had grown a great deal to the east. I was able to drive most of the way but had to cut and winch fallen trees out of the way and made it up to the abandoned Alder Ridge lookout tower and threw everything together with bailing wire and used my vise-grips to fasten one of the battery cables that had no end and tuned the duplexer as best as I could with limited gear.
By 3a.m., it was on the air but being part of a new system the tone coding was not compatible with the truck and packsets so went to the just being built fire camp and set up an assembly line to convert all the mobiles and packsets. This was completed by sunrise when the additional fire hand crews were arriving. Doing all that in the dark with blinding smoke was not easy.
The head dispatcher and head ranger were quite happy that for the first time in a dozen years something got done in the radio department. After things cleared a bit in 8 days, the radio tech showed up pissed that someone had installed the part of the system when he was not ready to do it, and he filed a complaint and wanted me arrested for "stealing and damaging" government property.
The head of the forest, who knew what happened and how dangerous those canyons were without radios for the hand crews, put the radio tech on administrative leave and wrote out a contract by hand in the middle of the dusty fire camp for my little company of 2 techs to take over the rest of the summer fire season. That was the first forest to have a contracted radio service and it worked really well so the entire state, 17 national forests, switched to that and we got the contracts for 3 adjacent national forests. It cost them less than maintaining the old techs who were all retirement age and highly resistant to changes and new technologies. For several years I kept my summer sessions to a minimum so I could be available for campaign fires since that was an area I knew well and loved, and had a horse ranch in the area. Every time I go back to visit the old timers talk about some of those times with fond nostalgia with me. Actually it was fun.

[Joe L]

Joe, 4 more days....
Not all contractors are bad.

Hey Stan! 1 more day left!!!!

Ah Motracs. I remember in the summer of '80 we had 27 days over 100 degrees. The germanium transistors in the front ends of the Motracs were popping like firecrackers from being covered with raincoats under the seat of the bucket trucks. I was just hired in March and by July I was telling the guys to just bring in the Motracs and I would fix them on the bench. All I did was take an RF voltmeter with a signal generator and make standard gain measurements (~20db) for each stage of the receiver of a working radio. Using those measurements, I could run thru a Motrac receiver in minutes.

The "tech" that trained me would spend hours trying to tune a radio hoping it would work good enough when finished. He is also the one that keyed a radio in his lap without the covers on. For those of you not familiar with these radios, they had tube outputs and used an inverter to convert the 12v to HV for the output tubes. It lit his arse up! He is also the one that told me to turn the element on a Bird 43 from reflected to forward power so we could get a radio check on a 300 watt base station. I asked him just what was dissipating the 300 watts in reflected mode and got the deer in headlights look.

But back to the point Stan, your small company is nothing like what they are looking at to contract out our services. They want a large company to offer what we do but so far are coming up dry. The first consultant (Ernest & Young), has returned an opinion that our department works in concert with too many departments to be able to outsource. Our CEO disagrees and has found another consultant that says it can be done.

But it is not my worry...

..Joe - Musician, Ham, woodworker, R/C enthusiast and amp experimenter.

[Steve Conner]

Enjoy your last day, Joe L!

That's the great thing about consultants, if you don't get the answer you want, just hire another one.

I don't get the comment about the Bird 43. Did the guy not realise that the signal still passes through no matter which way the slug is turned? Maybe he thought it worked like some sort of stopcock for radio waves.

[km6xz]

Joe, that was something nice and simple about RF systems, they either made spec or something was wrong. If a receiver model was spec's at -127db, for some specified SINAD, if it did not make that you knew it needed repair or alignment. Such consistency was not part of the audio world, particularly now MI gear that. Motorola had stage gain specs in their manuals.
The little company was eventually sold when we got up to 6 techs and 4 support staff but we had thousands of radios under contract. It was very seasonal, most of the Forest Service gears was stored all winter but we got paid a monthly fee per unit. We also did two counties that included sherif and ambulance, and dozens of fire departments and log trucking companies. So there was a lot of work in the summer and not quite as much in the winter when everything was under a couple feet of snow anyway. I still have one of the Motorola Service Monitors here in Russia....smuggled in...but the IFR's went with the sale. I really liked the IFRs.

Happy retirement!

[Joe L]

Enjoy your last day, Joe L!

That's the great thing about consultants, if you don't get the answer you want, just hire another one.

I don't get the comment about the Bird 43. Did the guy not realise that the signal still passes through no matter which way the slug is turned? Maybe he thought it worked like some sort of stopcock for radio waves.

First off, sorry Enzo for highjacking the thread.

I did enjoy it Steve! It was really strange to return from my luncheon with the home office guys to my office where I left the van and keys and closed the door realizing that I couldn't go back in legally.

But the 4 stout Tequila Sunrises back at the house took the edge off

RE the Bird meter, I looked at him and asked just what in the wattmeter was dissipating the 300 watts (tube, class C) of the base with the slug reversed. To this day I give him grief about that.

Hmmm.... I still have a pair of unused 8560AS Eimac triodes that base used. All I need is a 2KV supply to make a p/p audio amp with them

[Joe L]

Joe, that was something nice and simple about RF systems, they either made spec or something was wrong. If a receiver model was spec's at -127db, for some specified SINAD, if it did not make that you knew it needed repair or alignment. Such consistency was not part of the audio world, particularly now MI gear that. Motorola had stage gain specs in their manuals.

They did provide gain measurements in the later models, but surely not in the Motrac, Mocom days. All they gave was a speced sensitivity of ~.25uV for 20 db quieting. SINAD came a bit later and was what I used. None of the other techs that worked on radios would go thru the trouble to hook up the SINAD meter and actually just used their ear to judge the 20 db quieting. That's why they picked me for any large scale technical projects involving the RF system. Like the rest of you guys, I love researching and solving a problem!

Happy retirement!

Thank you! I think I will get used to this real quick.

[Enzo]

Don't apologize to me, I didn't start the thread. It just had my name in it.

[km6xz]

Yes, you are right about the Motracs manuals not having it but it was included in later generations, where most of the gear we worked on was of the Micor era. I had collected a lot of Motracs because I was able to get into state surplus sales and I was buying buying them up for use in the Pioneer Volunteer Fire Department, to replace their pre-prog GEs dating from the middle 50s and not even legal anymore.
I donated 40-50 of the Motracs of different versions and even had a hi-band 100watter under my seat of my FJ40 Landcruiser which worked well until I got a Micor, which was replaced by a SyntorX used on 2 meter ham. I designed and built a dash mounted head with thumb wheel direct frequency selection. The Forest Service system was a mess of lowest bidder gear, most of the mobiles were Aerotron which were a pain for such rugged service where they never saw a paved road.

One day the Forest Service head dispatcher called me at the studio and asked me to help track down a jammer that was popping up frequently. The next time I was up there in the mountains I went to visit the dispatch center and asked for background information and asked lots of questions. There was some consistency in the times and days of the unmodulated carrier on their main channel that had picket fence noise at times so was obviously moving.
They were in a panic over the situation that started at the beginning of the season. It would come on and last for 15-20 minutes, and sometimes would be bursts of a few seconds each. As people filled in more details and their memory, it seemed to me not to be some malicious jammer but they wanted the FCC and FBI called in.
I set up my receiver on input at the times their log books said were the most frequent occurrences. I found that it was not one transmitter but a couple since they had slightly different carrier frequencies, 40-50 hz.
Nothing made sense that it was an intentional jammer, nor was it likely for drivers sitting on their mics as the head dispatcher claimed. I figured there was less human intent than anyone was willing to accept. As the stories filled in more details I checked the logs for times over the previous weeks it was happening, and noticed a curious trend, the start times were getting earlier by a few minutes every day but some were out of that trend and seemed random. Some days nothing was found in the logs so I asked for staffing records to see who was on which days who had vehicles. I sent a tech out to one of the ranger stations that seemed to have the most staff on patrols on the days that it was happening, thinking that something might be screwing up in the mobiles. Nothing was found.
I still felt it was too methodical to be a jammer and it occurred to me that checking the weather on hourly basis over the prior few weeks revealed that it did not happen on rain or heavy overcast days. I reasoned that something was weather related and thought back from own travels in those regions of the forest where people would be at various times of day and told the dispatcher I figured it out, I knew what was jamming the system without even getting within 25 miles of the area. A few beers were bet on the solution, everyone said I was joking or crazy. I had been on those roads a lot and realized that weather, or more specifically, sun, was a big variable. It occurred in the afternoon and did not matter too much who was on duty. I remembered that driving one road in the suspect district was on a ridge line that required me to adjust my rear view mirror most times if I drove back to the district station due in the late afternoon. It was the only place in the heavily forested district where sun would be shining directly on my mirror and therefore on the dash of my LC. The Aerotrons needed to me modified to accept a Barco touchtone pad, by the factory and the TT pads were mounted on the dash. I knew the circuit and the pads had PTT lines besides signal and power. They had a LED power indicator on the pad. Logic told me the late afternoon sun was causing leakage in the LED which trigger the PTT line. I told the dispatcher to send a memo to all stations to cover the led with black electrical tape until we could get all the stations to fix it. Sure enough, testing it revealed that direct sun falling on the keypad LED consistently triggered the transmitter. Aerotron did not know it since this was the only special supply contract they had for such a combination. I added another transistor and a resistor that prevented that to the 110 mobiles that had that feature.
The days it did not occur were overcast or rain days. It occurred more when higher fire danger alerts were in effect so there were more patrols. One of the log entries indicated there was a beat tone on one of the days which would have indicated two transmitters on the air at the same time, and that day was designated as a training day so it was logical that more than one truck was traveling together.
Sometimes(actually, always) logic wins the day over brute force methods or shotgunning. So that is my Aerotron story....

[Steve Conner]

Nice piece of troubleshooting ... Also another thing for us to add to our in-house design checklist.

[J M Fahey]

Sometimes(actually, always) logic wins the day over brute force methods or shotgunning. So that is my Aerotron story....

NO NO NO, you are WRONG

You must replace all those thingies inside to repair it.
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PS: can I triple like your post?

[km6xz]

Don't get me started on shotgunning.......As some who have commented before, a lot of people disagree with my pet peeve; shotgunning.
When I hired techs it was one of the first lessons they had to learn or else not work for me. They would argue that replacing all the parts serially until the symptom went away was the only way to take care of some problems. I countered that as a pro tech, there is more to a repair than making the symptoms go away, just as important is making the repair reliable and long lived. Without isolating the cause and understanding the mechanism of fault, the repair can never be considered complete or trustworthy.

A repair might seem profitable by making the symptoms go away and getting paid but a whole chain reaction of losses occur if the cause of the symptoms is not determined accurately and resolved. A shop gets to do the repair over again, and lose reputation, lose available time to do positive work that IS for pay, which also enhances the reputation, and lowers other overhead. There is no good outcome for bottomline or or reputation if returns are more than a couple percent. Some shops I know of were tolerating 25-30% return rate.

Shotgunning and not employing good diagnostic principles almost assures poor odds in generating a positive reputation, earning a profit and being able to charge reasonable rates. Bad techs and shops who employ them have to charge more due to ineffectiveness, lack of diagnostic skills means longer bench times and lack of understanding the systems involved increases the number of perfectly good parts are replaced and charged to the customer. That is fraud. There are a LOT of hacks out there who should not be messing with customer's gear, and I do not like to encourage them on this forum. Owners seeking advice, who take responsibility for their actions are another class who should be encouraged but not commercial shops charging for the implied technical expertise they trade on, but do not have.
A common theory promoted on this forum is restoring items while repairing it. The most common is doing a "cap job". Well, that is pretty amateur, in my opinion and leads to lower reliability. It also can hide the real cause of why it needed repair in the first place. Only replace parts for which a reason to has been proven.

[Tom Phillips]

+1 on all your points.

...There are a LOT of hacks out there who should not be messing with customer's gear...

The prevalence of the hacks is an unfortunate side effect of the availability of on-line advice. I have no problem with people asking questions to support their learning. However, passing themselves off as professionals and charging high end rates for their hacks is certainly fraud.

An individual posted some very basic troubleshooting questions on this forum. The question showed that he lacked a basic understanding of circuit theory. Nothing wrong with that. However, he also posted a link to his web site and on that site he advertized that he specialized in vacuum tube amp repair. The nature of the statement implied that he was very competent and experienced. Maybe he was an unconscious incompetent. Never-the-less I think it WAS a form of fraud.

Tom

[g1]

km6xz, while I agree with you about shotgunning, it is important to distinguish between random guess shotgunning (which I think is what you mean) and routine replacement of old parts, or "scheduled maintenance", which may sometimes seem like shotgunning, but is not.
A couple examples, an amp with a fault you know is caused by a cap, and you know all caps are 50 years old, plus the customer wants a recap. So you replace them all, without first determining which one was causing the fault. Is this shotgunning?
Another example, you probably worked on the 2nd gen. Panasonic Dat's, SV-3700 and derivatives. They would develop a problem where the transport would make a loud squawking noise in high speed FF/REW. It was a worn gear in the transport, but which one? I had a hard time with their philosophy in training sessions, they insisted on replacing all the gears, even though just one was creating the problem. To me it was "shotgunning" but to them, it was the most economical for the customer (gears were cheap, labour was not), plus all gears were a bit worn, and the combined wear was a factor. They insisted that these were industrial machines and routine maintenance (like head replacement) should be on a schedule, similar to the aircraft maintenance model.
In the end, they broke me . But I still hated throwing out all those "good" gears. So I guess what I'm saying is there is sometimes shotgunning that may be allowable, or even desirable. But you could argue I am stretching the definition of shotgunning.