• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

Harris PT-5 FM transmitter

Z

zach_morton

Guest
I thought I'd throw this little irritation out to the board because I've gotten such great help before. The problem is with with a Harris PT5FM transmitter. This is a little solid state unit, and in having difficulty with the remote control samples coming from the controller. I've contacted Harris about this, and keep getting sent around in circles. The front panel is showing correct values, forward power, pa volts, currents, etc...but the sample voltages are way off. For instance, I'm getting +14.5V across the paV sample. That should be no more than +4v. My forward power sample wildly various up and down.

The only thing I've come across is by scrutinizing the schematic, and my guess is a resistor pack has fried. But, just wanted to see if anyone else has had this problem before I buy yet another part that doesn't fix it.
 
littlejohn said:
Never heard of that one. Does it use the same modules as the Z series?
Click to expand...

The PT series FM tx was the predecessor of the Z series. It uses entirely different r-f amplifiers, controller, power supply, and everything else.

RF (Harris FM Appl Engr, 1980-1999)
 
Wow. I have a PT-2CD in service with never a problem. I hope it lasts... That thing has never caused me any grief. Same with my DX-25 on another station. Wish I could say the same for the Harris/Gates 5's. Those stupid banana jack power connectors on the RF modules were a bad idea. Otherwise, they work well...

jd
 
The 5A series answered most of the concerns with the original 5. And the big AMs aren't bad boxes... loading coils and all. They were worth messing with for the electric savings if you replaced an older 25 or 50 with one.
 
jammerdave said:
Wish I could say the same for the Harris/Gates 5's. Those stupid banana jack power connectors on the RF modules were a bad idea.
Click to expand...

That's interesting. I've have several of the Harris "SX" and "Gates" series transmitters, both of which use the banana plugs on the RF amplifier boards, and have never had a problem with them. Some of those are about 20 years old.

The main problem I've encountered with those is the transistor sockets on the RF amplifier boards that used the TO-3 case MOSFETs. Over time they make poor contact and cause transistors to operate intermittently. You end up having to replace all of those tiny pin sockets. They corrected this issue later in the "Gates" series production run by using TO-220 case MOSFETs and screw terminals.
 
Next time you're in one of the rigs with banana jack power plugs, check the tightness of the nut holding the jack in place. After having one burn up, I checked the rest and they were all a bit loose. Vibration over time, I'm guessing. When they get too loose, all that current draw results in arcing, and then destroying the board. Big time flameout in my case...

df
 
Along those same lines, if you got a Z series, it's a real good idea to tak eeach module out and tighten the cap screws which hold the amp pads to the heat sink. They loosen with temperature change, due to the dissimilar expansion characteriustics of the three metals involved (Steel screws, al\uminum heat sink, copper amp pads). Volkswagen used those silly compensating washers under the bolts, Harris should have. I can usually get a half turn on all of mine after a year of operation. I suspect in an ambient air operation, they'd loosen more.
 
Interesting.. I'll have to check that out on one I have next time I have it off. A couple things brought up here that I have to agree with about Hair-ass is that they are extremely bad about making stuff obsolete. Their parts are too high compared to others and many of their 'tech support' people offer very little help these days, when you can get to them. They wont accept calls except for someone being totally off the air after bankers hours. Personally I won't be buying any more of their stuff. The equipment itself and it's design isn't that bad, but unfortunatly the company that hangs around it has fallen behind others these days IMHO.
 
They tend to put things in the field about a year early... and they just bagged a bunch of folks in Quincy. They're like the telcos - as soon as they get some folks up to speed on the product, they have a bad year and fire all of them. I find the Continental and BE product somewhat better laid out, and with fewer of what looks like afterthoughts in them. And I find their field service folks substantially easier to deal with and somewhat more knowledgeable about their product. I apologized to the last Harris tech type's boss when I finally got him opn the phone. I'm sure the original gent had good knowledge of the product, but his accent was such that, in a noisy envoronment, he was unintelligible. I wasn't out to offend the guy, but I also hadn't the time to go find a phone downstairs where I could understand him. Maybe the water cooled three-bay isn't such a bad idea after all... I bet it's quiet.
 
Agreed on your points about Harris. I don't know if anyone else sees the parellel here, but Harris reminds me of Motorola in a lot of ways. They have some pretty good engineering but overuse the "obsolete" excuse way too much. They charge plenty for their stuff, but next year they tell you it's out of date and therefore you need to buy the latest and greatest thing. In the case of Motorola, there are cities that have ended up having to throw away their entire radio systems after less than 7 years because no one at Big M could keep the crap running and keep parts for it. Harris generally gives you 10 before they start telling you they don't have your part anymore. Bad news is a 10 dollar gas-discarge tube will cost you 1400 within those 10 years. 5 chips for your digital STL that probably cost them 15 dollars will cost you 1800 within those 10 years. I realize there's costs associated with alleged 24/7 support (don't bother unless it's an "emergency" after banker's hours) that inflates parts costs, but...

I hate to see that they are slicing and dicing up their staff at Harris. Getting rid of people with a brain is the LAST thing that big bumbling company should do. Lack of consistancy and knowlege will eventually do them in if they don't watch out. A company is only as good as it's worst employee, and quite frankly what I've seen out of them they have no shortage of the unknowlegeable when it comes to Harris. I absolutely agree on the "putting it out a year too early" factor. They, like big M are real good about doing that. I guess they probably haven't considered that some people might be going elsewhere for their transmission equipment for some other reasons other than a soft market. Honestly I'd just like to see someone in Quincy pay attention and understand there's other places people can buy stuff and start acting like they aren't the only game in town. They've got the sales game down pretty good on major ticket items but that's about where it ends these days.

In general it's not a good thing to have people with thick accents as tech support personel. It has a tendency to make things more frustrating when in many cases the end user is already frustrated enough as it is.
 
Over the years I have always had great luck with their tech support after hours and weekends.

I do agree with you that they drop support on products too quickly.
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom