Tl922 mods

there other output? Magnificent idea and..

Tl922 mods

Batch split string

So far received 2 votes for a total score of 5. The scale is 1 - 10, with 1 being poor and 10 being excellent. Webmaster, add a Remote rating Related links We thought you might also be interested in these additional resources we selected from the same category: QSK for the TL and SB mods - Beautifully constructed amplifiers.

Unfortunately, are not suited for Measures, AG6K Real Hams review new sites every day sincefor potential inclusion in the Directory, and to evaluate the best place to list them. Sign up to our Newsletter Get our latest news and links in your email. Operating Modes Operating Aids.

CB Radio Antique Radio. Related links We thought you might also be interested in these additional resources we selected from the same category: QSK for the TL and SB mods - Beautifully constructed amplifiers.

Share this resource Share this link with your friends, publish within popular social networks or send it via email.

The DXZone is the largest human created and maintained library of web sites dedicated to Amateur Radio, currently lists Get our latest news and links in your email.

Service provided by Google FeedBurner. Visit Site.QRZ Forums. Looking for opinions Additional electrical bonding between the tuner chassis and the tube chassis, or sufficient as-is?

If additional recommended, what would be your preferred way to accomplish it? W4LACJun 5, I have reworked numerous amps. I find the original parasitic suppressors to be just fine. I would leave them.

Kenwood TL-922A Modifications

I would ground the grids and perform the "self bias" mod to protect the filament transformer. Add a glitch resistor. A 1n diode on the minus rail is also good.

tl922 mods

W1QJJun 5, VK6APZ likes this. Some of his stuff is questionable and I would stay away from. Many salespeople create problems that do not exist so they can sell solutions to non problems.

Be wary. The hairpin suppressors were determined not to be as affective as a resistor with turns of wire around the resistor body. N8FVJJun 6, WG7X likes this. Last edited: Jun 7, G0HZUJun 7, You must log in or sign up to reply here. Show Ignored Content. Share This Page. Your name or email address: Password: Forgot your password?

tl922 mods

Register for a free QRZ account.It's not the first time I've scratch built a TL from a collection of original parts acquired from various 2nd hand parts sources on-line but this is the first time I've attempted to document the process. I started collecting the parts for this project in or earlier so it has been a slow process for me. The TL was a well designed and mechanically sound H. Linear Amplifier built for the Amateur Bands in the 's. It's mechanical construction is equal to or better than any others I have seen offered for sale in that era.

The circuitry is very basic and mostly reliable given the thousands of units that would have been manufactured over the years of production. There was no emphasis given to protection circuitry other than the basics. Also of note, is the fact that there were really no changes to the circuitry, if any at all, that I am aware of from the first to last production units. This says something about the quality of the original design!

I have also rebuilt at least four of these TL amplifiers from parts acquired on eBay USA and other used parts sites here and overseas. It has not been the cheapest way to go but I have enjoyed the experience and learned somethings along the way.

Bias Circuit Modifications. The circuit to the left is an update I have used a number of times. It provides for electronic bias and sequencing of the RF in and RF out contacts of the two antenna relays. Not shown but also a recommended addition is back to back diodes across both meters.

These can be 1N or 1N types. Their part No. A 5 Volt version is also available from Jaycar and its part number is SY The resistance of R2 would need to be adjusted for the 5V drop. The manufacturer is Hongfa Electronics. No doubt there are many other options available. On the right is the oscilloscope display of the antenna relays contact timing. This ensures that the output relay is never "hot switched". Three TL chassis awaiting a rebuild and will progress these as time permits.

The photos below are some my current TL rebuild projects that as yet have not progressed too far. In the bottom row of the photos below you may notice that it is not an original band change switch.

Muti-tech Industries make a heavy duty drop-in replacement. A pair of new Z tubes were purchased in March and the chassis with all major hardware has been assembled. The paintwork has been redone and the front panel has been screen printed professionally. I intend to progress this TL rebuild as soon as possible after my current project, A ham band receivernears completion. Page last updated 05 August Transmit Frequency Range……………………… m through 10 m amateur bands.

Excitation Energy Required ……………………. Rated Plate Input …………………………………. Plate Voltage at No signal ……………………. Circuit Type …………………………………………. Class AB2 grounded grid linear amplifier. Below —30 dB. Input Impedance…………………………………… Output Impedance …………………………………50 to 75Q, unbalanced. Cooling …………………………….

Wok stand

Forced Air. Interlock Safety Features ………………Primary high voltage circuit cut-off Secondary high-voltage circuit grounding. Thermal Protector …………………………………. Locks out transmit relays if power transformers overheat. Fan Motor Delay Stop Time…………………….

Power Tubes Used …………………………………Eimac Z, two pieces. Semiconductors …………………….

Unlimited storage telegram

Power Requirements……. Cables Supplied…………………… Power cable with 2-pin grounding plug, 2 m long Signal cable coaxial with M-type connector. Weight ……………………………….

Kenwood TL-922

Net 31 kg 68 lbs. Shipping 38 kg 83 lbs. Voltage……………………………………………………… 5. Current…………………………………………………… Direct Interelectrode Capacitances grounded grid 2. Operating Position………………. Vertical, base down or up. Plate Seal………………………………………………. Radiation and forced air.

DC Plate Voltage……………………………………. DC Plate Current…………………………………. Plate Dissipation……………………………………. Grid Dissipation………………………………………. TL Users manual Kb. Reviving a Modified Kenwood TL Cookies on this site are used to personalize content and ads, to provide social networking features and analyze traffic.

We also share information about your use of the website with our partners social networking, advertising and web analytics who can combine it with other information provided to them or they have gathered from the use made of its services. Find out more.I hope this article might be useful to all whom have burn the switch band of TL As most of you knows the switch-band is no longer available in the market.

When I learned from internet that someone has substituted the switch-band with a Vacuum-Relais I decided to try this. I bought a dozen of Kilovac HC This is the component to be blamed for the damages to the switch band.

I have noted some signs of burning on the contacts and when I tried to activate it manually I noted that firs the first it was closed the ingress contact and than that of the antenna.

Ruby vs garnet wine

This men that the power was not sent directly where needed and the contacts of the switch band were burned. Had I changed this with two Vacuum-Relais I would have immediately resolved the problem.

I strongly recommend this changes to all owners of TL It does not cost a lot and resolve many problems of this amplifier. Remove the top and…. Cookies on this site are used to personalize content and ads, to provide social networking features and analyze traffic. We also share information about your use of the website with our partners social networking, advertising and web analytics who can combine it with other information provided to them or they have gathered from the use made of its services.

Find out more.This link is listed in our web site directory since Thursday Jan 26and till today " Mods for the Kenwood TL " has been followed for a total of times. So far received 1 votes for a total score of 2. The scale is 1 - 10, with 1 being poor and 10 being excellent. Webmaster, add a Remote rating Related links We thought you might also be interested in these additional resources we selected from the same category: QSK for the TL and SB mods - Beautifully constructed amplifiers.

Unfortunately, are not suited for Measures, AG6K Visit this link Mods for the Kenwood TL Visit Site Share this resource Share this link with your friends, publish within popular social networks or send it via email. Real Hams review new sites every day sincefor potential inclusion in the Directory, and to evaluate the best place to list them.

TL-922 Mods

Sign up to our Newsletter Get our latest news and links in your email. Operating Modes Operating Aids. CB Radio Antique Radio. Mods for the Kenwood TL Related links We thought you might also be interested in these additional resources we selected from the same category: QSK for the TL and SB mods - Beautifully constructed amplifiers.

Share this resource Share this link with your friends, publish within popular social networks or send it via email. The DXZone is the largest human created and maintained library of web sites dedicated to Amateur Radio, currently lists Get our latest news and links in your email. Service provided by Google FeedBurner. Visit Site.Kenwood TL Amplifier. As with any old gear and our modern Internet, there are many needless and sometimes detrimental mods published for the Kenwood TL and TLA amplifier.

I don't believe any of this is malicious or intentional, it is just a byproduct of bad information, experimental guesswork, and a desire for one simple answer to a variety of causes and cures. Well intentioned Hams think they have found a universal cure, even when the modification is detrimental to how the system works and contrary to good engineering practices, because a small sample of one or two unitsoften improperly tested, appears to function OK. That's not much of a surprise if we think about it.

When a bad component or components, in use for ten or twenty years or more before failure, are replaced Then, when the system works, the needless change immediately gets credit for improving things.

tl922 mods

One single source has diligently worked to convince amateurs that nearly every arc, spark, pop, bang, component, or tube failure is a parasitic. This source, of course, is the only source for the "true" cure. Send him money, and every cause of past and future component failure is magically cured.

Never mind that Eimac engineers, and virtually everyone else experienced in RF engineering or power grid tubes, finds fault with most everything he claims. Of course the natural defense is there is an "industry wide conspiracy" to discredit him, and to sell customers bad systems. Everyone likes a good conspiracy theory, the Discovery Channel and other networks capture the imaginations of viewers by presenting "evidence" of ancient aliens, big foot, and an occasional appearance of Elvis.

If a larger cross section of viewers were amateurs, no doubt they would have an "Ancient Parasitic" show, tying Egyptians and pyramids to optimum shapes of nichrome parasitic suppressors. A radio friend spent a great deal of money and time having his Kenwood TL amp modified. Despite a great deal of work, his amplifier never worked correctly for any length of time. This amplifier had the full treatment, including nichrome hairpins, but they had to be removed because of "parasitics" or instability.

I have no idea if the amp was initially stable or not, but my best guess is his amplifier originally never had a parasitic. Most likely, as with nearly all other amplifiers, it simply had some bad year-old parts.

The only arc I witnessed in this TL linear was from a bandswitch wire routed too close to another wire. This amplifier arrived with well-cooked RF Parts Z's. The tubes were about 2 years old, and were very low on emission despite all the filament voltage, nichrome, and inrush modifications. While parasitics certainly can occur, they are grossly exaggerated in an effort to sell magical suppression kits.

Parichay episode 128

There is no reason to guess! An explanation of causes and cures for instability is at the above page and links from the page VHF Stability. At least it did not arrive with the hairpin suppressors installed! There is no reason to be "neat" in a tank circuit or RF system, and angle wires at 90 degree bends. Squared corners and right angle wiring, unless carefully planned, is almost always detrimental to circuit performance.

tl922 mods

If you read the linked page on VHF parasitic stability, you will understand why anode-to-chassis and anode-to-grid paths must be short. The parasitic suppressor, to be most effective, must have significant impedance compared to the path from anode inside the tube to the chassis and back to the grid RF signal common ground point.

When we use long thin circuitous wiring in the anode system, we make a parasitic suppressor of a given VHF loss resistance much less effective. The 15 ohm HV fault limiting resistor at the middle-top is a good thing, even if not the best style resistor.

A better style would be a P pulse rated resistor. The anode path was a problem, though.

Kenwood Tl-922 repair and modifications

Not only was path length needlessly long from the modifications, a small resistance element was added. It reduces upper HF tank unloaded Q that should be high for maximum efficiencywhile reducing effectiveness of the anode-to-plate choke VHF suppressors. Not only that, it was a short straight wire shunting a tiny loop.

There isn't any logical RF rational for an odd wiring system like that. The TL had the wrong type of capacitors at CL. These caps need to be temperature-stable high-current capacitors.


Junos

thoughts on “Tl922 mods

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top